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Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for elucidating the molecular makeup of materials. It possesses the unique characteristics of single-molecule sensitivity and extremely high specificity. However, the true potential of SERS, particularly in capturing the biochemical content of particles, remains underexplored. In this study, we harnessed transformer neural networks to interpret SERS spectra, aiming to discern the amino acid profiles within proteins. By training the network on the SERS profiles of 20 amino acids of human proteins, we explore the feasibility of predicting the predominant proteins within the µL-scale detection volume of SERS. Our results highlight a consistent alignment between the models predictions and the proteins known amino acid compositions, deepening our understanding of the inherent information contained within SERS spectra. For instance, the model achieved low root mean square error (RMSE) scores and minimal deviation in the prediction of amino acid compositions for proteins such as Bovine Serum Albumin (BSA), ACE2 protein, and CD63 antigen. This novel methodology offers a robust avenue not only for protein analytics but also sets a precedent for the broader realm of spectral analyses across diverse material categories. It represents a solid step forward to establishing SERS-based proteomics.

Nanozymes, as an emerging class of enzyme mimics, have attracted much attention due to their adjustable catalytic activity, low cost, easy modification, and good stability. Researchers have made great efforts in developing and applying high-performance nanozymes. Recently, transition-metal-based nanozymes have been designed and widely developed because they possess unique photoelectric properties and high enzyme-like catalytic activities. To highlight these achievements and help researchers to understand the research status of transition-metal-based nanozymes, the development of transition-metal-based nanozymes from material characteristics to biological applications is summarized. Herein, we focus on introducing six categories of transition-metal-based nanozymes and highlight their progress in biomarker sensing and catalytic therapy for tumors. We hope that this review can guide the further development of transition-metal-based nanozymes and promote their practical applications in cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Recently, gold nanomaterials have been rapidly developed owing to their high stability, good biocompatibility, and multifunctionality. The unique catalytic activity of gold nanomaterials has driven the emergence of the concept for a "gold nanozyme." Understanding the characteristics of gold nanozymes is crucial for improving their catalytic performance as well as expanding their applications. In this review, we provide an overview of the intrinsic enzyme-like activities of gold nanozymes, including peroxidase-, catalase-, superoxide dismutase-, and glucose oxidase-like activities, and the catalytic mechanisms involved. In addition, strategies for modulating the catalytic activity of gold nanozymes and their applications in biosensing were discussed in detail. Moreover, we highlight the current challenges of gold nanozymes and look forward to attracting more attention for propelling the developments in this field. [ABSTRACT FROM AUTHOR]

The capability of plasmonic nanostructures in generating superchiral near‐fields holds great potential for a wide range of applications, including enantioselective sensing, medical diagnosis, and chirality‐based bioimaging. To implement high‐performance chiral nanophotonic devices, achieving in situ tuning of chiroptical activity in plasmonic nanostructures is highly desirable yet remains a formidable challenge. Here, a straightforward method is developed for deterministic assembly of plasmonic nanosphere trimers using spectroscopy‐assisted nano‐manipulation. The technique offers in situ, real‐time, and site‐specific control over the chiroptical response of trimers by adjusting their vertex angle and in‐plane orientation. The combination of numerical simulations with the Born‐Kuhn model reveals that oblique excitation effectively induces the symmetry breaking of the trimer structure, resulting in a preferential response of two distinct hybridized plasmonic modes to the handedness of light. Consequently, this yields a significant chiroptical response with the g factor up to 0.37. Remarkably, the trimer with an optimized obtuse angle exhibits a 193‐fold enhancement of optical chirality density, enabling the detection of molecular chirality with a record‐large spectral dissymmetric factor of 12 nm. The study facilitates the rational design of plasmonic nanostructures, offering promising prospects for chiral sensing at the single‐molecule level and asymmetric photocatalysis. [ABSTRACT FROM AUTHOR]

Measurements of the refractive index of liquids are in high demand in numerous fields such as agriculture, food and beverages, and medicine. However, conventional ellipsometric refractive index measurements are too expensive and labor‐intensive for consumer devices, while Abbe refractometry is limited to the measurement at a single wavelength. Here, a new approach is proposed using machine learning to unlock the potential of colorimetric metasurfaces for the real‐time measurement of the dispersive refractive index of liquids over the entire visible spectrum. The platform with a proof‐of‐concept experiment for measuring the concentration of glucose is further demonstrated, which holds a profound impact in non‐invasive medical sensing. High‐index‐dielectric metasurfaces are designed and fabricated, while their experimentally measured reflectance and reflected colors, through microscopy and a standard smartphone, are used to train deep‐learning models to provide measurements of the dispersive background refractive index with a resolution of ≈10−4, which is comparable to the known index as measured with ellipsometry. These results show the potential of enabling the unique optical properties of metasurfaces with machine learning to create a platform for the quick, simple, and high‐resolution measurement of the dispersive refractive index of liquids, without the need for highly specialized experts and optical procedures. [ABSTRACT FROM AUTHOR]

2D materials, owing to their nearly atomic thickness, have emerged as promising candidates across a broad spectrum of next‐generation devices and systems. In the post‐graphene era, molybdenum‐based dichalcogenides (MoX2, where X = S, Se, Te), possessing a graphene‐like structure, represent one of the most promising subsets among 2D transition metal dichalcogenides (TMDs) due to their extensively researched and distinctive electronic, optical, and mechanical properties. Further with their distinct properties of different phases (2H, 1T) make it attractive for both fundamental and applied research. It finds diverse applications, spanning from optoelectronics to catalysis and sensor development. In this review article, the unique crystal structural properties of MoX2 are highlighted and their different synthesis methods, incorporating recent advancements in synthesis approaches discussed. Subsequently the recent development of MoX2 nanocomposite based on carbon, metal, metal oxide and various polymer discussed. Finally, the key challenges impeding the advancement of sensing applications and propose avenues for future development, drawing upon the current progress in 2D MoX2 and their nanocomposites also find mention in this review. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) proves to be one of the most effective methods of label-free detection and has been integral for the study of biomolecular interactions and the development of biosensors. This trend delves into the latest SPR research and progress built upon the Kretschmann configuration, a pivotal platform, and highlights three key developments that have enhanced the capabilities of the technique. We will first cover a range of explorations of novel plasmonic materials that have shaped SPR performance. Innovative signal transduction and collection, which leverages traditional materials and emerging alternatives, will then be discussed. Finally, the evolving landscape of data analysis, including the integration of machine learning algorithms to navigate complex SPR datasets, will be reviewed. We will also discuss the implementation of these improvements that have enabled new biosensing functions. These advancements not only pave the way for enhanced biosensing in general but also open new avenues for the technique to play a more significant role in research concerning human health. [ABSTRACT FROM AUTHOR]

Electrochemiluminescence (ECL) detection is widely applied in many fields, including chemical measurement, biological analysis, and clinic tests, due to its high sensitivity. Currently, the fast development of many new electrochemical luminophores is continuously improving the ECL-based detection ability. Besides the enhancement of luminescence emission for a high detection sensitivity, minimizing the effect of co-reactants on ECL detection and achieving multiple analysis in one sample are also the main directions in this field. This review focuses on a summary of recently prepared new luminophores to achieve the three aims mentioned above. Especially, the review is composed by three parts, focusing on the luminophores or materials with high ECL efficiency, self-enhancing properties, and multi-color ECL luminophores. The fabrication of biosensors using these molecules is also reviewed to exhibit the advances in biological applications. [ABSTRACT FROM AUTHOR]

Over the past three decades, plasmonic nanostructures, particularly spherical ones, have seen remarkable advancements. Recently, attention has shifted toward anisotropic nanoparticles, especially star‐shaped/branched structures such as plasmonic nanostars (PNS), due to their distinct properties. PNS offers superior electromagnetic enhancement effects, larger surface areas, and as well as non‐linear and unusual photothermal properties, setting them apart from spherical counterparts. Despite significant progress in synthetic methods and characterization of the particles, challenges remain in transitioning PNS technology into practical use. In this perspective article, the distinctive attributes of PNS in biosensing applications are discussed, beginning with an exploration of synthesis methodologies. Their optoelectronic properties are examined and discussed how these properties influence their interaction with different molecules from a biosensing perspective. With a focus on PNS, detailed insights are offered into their unique properties, current applications, and future potential. By fostering discussion and understanding of PNS development, this article aims to facilitate the translation of PNS technology into practical applications, encouraging targeted improvements and advancements. [ABSTRACT FROM AUTHOR]

Nucleic acid‐based molecular recognition plays crucial roles in various fields like biosensing and disease diagnostics. To achieve optimal detection and analysis, it is essential to regulate the response performance of nucleic acid probes or switches to match specific application requirements by regulating thermodynamics and kinetics properties. However, the impacts of thermodynamics and kinetics theories on recognition performance are sometimes obscure and the relative conclusions are not intuitive. To promote the thorough understanding and rational utilization of thermodynamics and kinetics theories, this review focuses on the landmarks and recent advances of nucleic acid thermodynamics and kinetics and summarizes the nucleic acid thermodynamics and kinetics‐based strategies for regulation of nucleic acid‐based molecular recognition. This work hopes such a review can provide reference and guidance for the development and optimization of nucleic acid probes and switches in the future, as well as for advancements in other nucleic acid‐related fields. [ABSTRACT FROM AUTHOR]

Sensing and imaging of biomolecules are crucial to disease diagnosis, prognosis, and therapy where optical techniques have essential utility. Untethered and remotely controlled micro/nanorobots have shown promising sensing and imaging capabilities, especially in complex biological environments. In this review, how micro/nanorobots are used for optical biosensing and imaging while highlighting the significant developments in the field is discussed. Starting is done by exploring colorimetric biosensing methods enabled by micro/nanorobots. Significant advancements in surface‐enhanced Raman spectroscopy‐integrated micro/nanorobots are reviewed. Further, state‐of‐the‐art optical bio‐imaging applications by micro/nanorobots at in vitro intracellular level are highlighted. Novel in vivo bio‐imaging assisted by optical micro/nanorobot sensors is examined. Furthermore, innovations in micro/nanorobots are assessed where motion augmentation is used as a detection mechanism, with applications in point‐of‐care molecular diagnostics. Finally, the challenges associated with micro/nanorobots‐assisted advanced optical biosensing and imaging while discussing insights about potential research directions for this rapidly progressing field are summarized. [ABSTRACT FROM AUTHOR]

A dual-emission fluorescent biosensing method was developed for simultaneous determination of CaMV35S and NOS in genetically modified (GM) plants. Two designed hairpin DNA (H1, H2) sequences were used as templates to synthesize H1-AgNCs (λex = 570 nm, λem = 625 nm) and H2-AgNCs (λex = 470 nm, λem = 555 nm). By using H1-AgNCs and H2-AgNCs as dual-signal tags, combined with signal amplification strategy of magnetic separation to reduce background signal and an enzyme-free catalytic hairpin assembly (CHA) signal amplification strategy, a novel multi-target fluorescent biosensor was fabricated to detect multiple targets based on FRET between signal tags (donors) and magnetic Fe3O4 modified graphene oxide (Fe3O4@GO, acceptors). In the presence of the target NOS and CaMV35S, the hairpin structures of H1 and H2 can be opened respectively, and the exposed sequences will hybridize with the G-rich hairpin sequences HP1 and HP2 respectively, displacing the target sequences to participate in the next round of CHA cycle. Meanwhile, H1-HP1 and H2-HP2 double-stranded DNA sequences (dsDNA) were formed, resulting in the desorption of dsDNA from the surface of Fe3O4@GO due to weak π-π interaction between dsDNA and Fe3O4@GO and leading to the fluorescence recovery of AgNCs. Under optimal conditions, the linear ranges of this fluorescence sensor were 5 ~ 300 nmol L−1 for NOS and 5 ~ 200 nmol L−1 CaMV35S, and the LODs were 0.14 nmol L−1 and 0.18 nmol L−1, respectively. In addition, the fluorescence sensor has good selectivity for the detection of NOS and CaMV35S in GM soybean samples, showing the potential applications in GM screening. [ABSTRACT FROM AUTHOR]

Many clinical procedures and biomedical research workflows rely on microscopy, including diagnosis of cancer, genetic disorders, autoimmune diseases, infections, and quantification of cell culture. Despite its widespread use, traditional image acquisition and review by trained microscopists is often lengthy and expensive, limited to large hospitals or laboratories, precluding use in point‐of‐care settings. In contrast, lensless or lensfree holographic microscopy (LHM) is inexpensive and widely deployable because it can achieve performance comparable to expensive and bulky objective‐based benchtop microscopes while relying on components that cost only a few hundred dollars or less. Lab‐on‐a‐chip integration is practical and enables LHM to be combined with single‐cell isolation, sample mixing, and in‐incubator imaging. Additionally, many manual tasks in conventional microscopy are instead computational in LHM, including image focusing, stitching, and classification. Furthermore, LHM offers a field of view hundreds of times greater than that of conventional microscopy without sacrificing resolution. Here, the basic LHM principles are summarized, as well as recent advances in artificial intelligence integration and enhanced resolution. How LHM is applied to the above clinical and biomedical applications is discussed in detail. Finally, emerging clinical applications, high‐impact areas for future research, and some current challenges facing widespread adoption are identified. [ABSTRACT FROM AUTHOR]

The emergence of CRISPR/Cas systems has revolutionized the field of molecular diagnostics with their high specificity and sensitivity. This review provides a comprehensive overview of the principles and recent advancements in harnessing CRISPR/Cas systems for detecting DNA and RNA. Beginning with an exploration of the molecular mechanisms of key Cas proteins underpinning CRISPR/Cas systems, the review navigates the detection of both pathogenic and non-pathogenic nucleic acids, emphasizing the pivotal role of CRISPR in identifying diverse genetic materials. The discussion extends to the integration of CRISPR/Cas systems with various signal-readout techniques, including fluorescence, electrochemical, and colorimetric, as well as imaging and biosensing methods, highlighting their advantages and limitations in practical applications. Furthermore, a critical analysis of challenges in the field, such as target amplification, multiplexing, and quantitative detection, underscores areas requiring further refinement. Finally, the review concludes with insights into the future directions of CRISPR-based nucleic acid detection, emphasizing the potential of these systems to continue driving innovation in diagnostics, with broad implications for research, clinical practice, and biotechnology. [ABSTRACT FROM AUTHOR]

Single-atom nanozymes, with their atomically dispersed metal active sites, distinctive atom utilization rate, and tunable electronic structure, demonstrate great promise in the field of sensing analysis. This paper reviews the latest research progress on single-atom nanozymes in sensing applications. We classify single-atom nanozymes based on both their structural characteristics, such as carbon-based carriers, frameworks and their derivatives, metal oxides, metal sulfides, and organic polymer carriers, and their unique catalytic properties, including peroxidase, oxidase, catalase, superoxide dismutase, and multi-enzyme mimetic activities. Furthermore, we discuss the application of single-atom nanozymes in the sensitive detection of biological small molecules, antioxidants, ions, enzyme activities and their inhibitors, as well as cells and viruses. Finally, we highlight the opportunities and challenges for advancing the practical application and further research of single-atom nanozymes in the field of sensing analysis. [ABSTRACT FROM AUTHOR]

Inorganic nanoparticles are a critical component in a broad range of applications spanning catalysis, sensing, optics, and electronics. The nucleation and growth mechanisms involved during their synthesis are known to be crucial for controlling their final performance. Macromolecules can display sequence definition, inherent chirality, metal ion targeting moieties, and can also form self-assemblies, affording them the ability to not only stabilize but also precisely control the synthesis and organization of nanoparticles for an intended application. Herein, we report the recent trends in inorganic nanoparticle synthesis mediated by peptides, peptoids, DNA, other biopolymers, and synthetic polymers. Important design parameters and future trends are also discussed. [ABSTRACT FROM AUTHOR]

The lanthanide complex, characterized by narrow emission bands, large Stokes shifts, long luminescence lifetime, robust resistance to photobleaching, and magnetic properties, affords significant promise for molecular imaging and biosensing applications. While most lanthanide complexes emitting visible light are extensively studied for cellular‐level detection and bioimaging, near‐infrared‐emitted (700–1700 nm) lanthanide compounds exhibit more favorable properties for bioimaging and biosensing, ascribed from deeper penetration and reduced bleaching effects. Besides, the magnetic lanthanide complex with higher magnetic resonance signals can enhance image resolution and sensitivity, offering more precise bioimaging analysis. However, the widespread use of high‐efficiency luminescence lanthanide complexes is currently impeded by the lack of design approaches for improving magnetic properties and sensitization chromophores with extended excitation and emission wavelengths. In this review, some fundamental theories and design strategies of lanthanide complexes are summarized for luminescence imaging, lifetime‐engineered imaging, magnetic resonance imaging, and dual‐modal imaging, and now highlight a selection of bioimaging and biosensing applications. The review addresses the existing gap in the literature by proposing some feasible approaches for improving the fluorescent and magnetic properties. Concurrently, future challenges and opportunities in the field of lanthanide complex probes are discussed. [ABSTRACT FROM AUTHOR]

Ionic conductive hydrogels (ICHs) have recently gained prominence in biosensing, indicating their potential to redefine future biomedical applications. However, the integration of these hydrogels into sensor technologies and their long‐term efficacy in practical applications pose substantial challenges, including a synergy of features, such as mechanical adaptability, conductive sensitivity, self‐adhesion, self‐regeneration, and microbial resistance. To address these challenges, this study introduces a novel hydrogel system using an imidazolium salt with a ureido backbone (UL) as the primary monomer. Fabricated via a straightforward one‐pot copolymerization process that includes betaine sulfonate methacrylate (SBMA) and acrylamide (AM), the hydrogel demonstrates multifunctional properties. The innovation of this hydrogel is attributed to its robust mechanical attributes, outstanding strain responsiveness, effective water retention, and advanced self‐regenerative and healing capabilities, which collectively lead to its superior performance in various applications. Moreover, this hydrogel exhibited broad‐spectrum antibacterial activity. Its potential for biomechanical monitoring, especially in tandem with contact and noncontact electrocardiogram (ECG) devices, represents a noteworthy advancement in precise real‐time cardiac monitoring in clinical environments. In addition, the conductive properties of the hydrogel make it an ideal substrate for electrophoretic patches aimed at treating infected wounds and consequently enhancing the healing process. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) conventionally occurs at the interface of a thin metallic film and an external dielectric medium in fiber optics through core‐guided light. However, this work introduces theoretical and experimental evidence suggesting that the SPR in optical fibers can also be induced through light scattering from Au nanoparticles (NPs) on the thin metallic film, defined as nanoparticle‐induced SPR (NPI‐SPR). This method adheres to phase‐matching conditions between SPR dispersion curves and the wave vectors of scattered light from Au NPs. Experimentally, these conditions are met on an etched optical fiber, enabling direct interaction between light and immobilized Au NPs. Compared to SPR, NPI‐SPR exhibits stronger field intensity in the external region and wavelength tuning capabilities (750 to 1250 nm) by varying Au NP diameters (20 to 90 nm). NPI‐SPR demonstrates refractive index sensitivities of 4000 to 4416 nm per refractive index unit, nearly double those of typical SPR using the same optical fiber configuration sans Au NPs. Additionally, NPI‐SPR fiber configuration has demonstrated its applicability for developing biosensors, achieving a remarkable limit of detection of 0.004 nm for thrombin protein evaluation, a twenty‐fold enhancement compared to typical SPR. These findings underscore the intrinsic advantages of NPI‐SPR for sensing. [ABSTRACT FROM AUTHOR]

Silver nanoparticles are among the most widely researched and used for nanotechnology-derived structures due to their extraordinary inherent optical properties, chemical stability, catalytic activity, and high conductivity. These idiosyncratic properties can be attributed to their unique physico-chemical characteristics, such as ultrafine sizes, high surface area, diverse shapes, and strong localized surface plasmon resonance. These distinctive features can be tailored using various physical, chemical, and biological synthesis methods. Various physical techniques are viable for producing silver nanoparticles on a large scale, but they suffer from drawbacks such as high-power consumption, expensive set-up, and limited control over nanoparticle size distribution. Chemical methods provide benefits like high yield, consistent shape and size distribution, and cost efficiency, but the residual toxicity of the chemicals involved hinders their biological applications. Biological synthesis approaches effectively overcome the limitations of both physical and chemical methods by eliminating the need for hazardous chemicals, requiring less energy, enabling diverse nanoparticle morphologies, and offering eco-friendliness and exceptional biocompatibility. The novel and promising properties of nanosilver-based biomaterials have been demonstrated to be suitable for a wide range of pharmacological and therapeutic biomedical applications. Their extensive application in wound healing, dentistry, cardiovascular disease treatment, nerve tissue engineering, cancer treatment, and biosensing can be attributed to their inherent antimicrobial and antibiofilm activity, antithrombotic properties, potential for nerve regeneration, photothermal conversion efficiency and sensitivity, respectively. This review discusses the different methods employed for synthesising silver nanoparticles and focuses on using nanosilverbased biomaterials for various biomedical applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: We report herein the first observation of MOF nanozyme enabling dual‐functional photo‐induced charge transfer and biomimetic precipitation for advanced organic photoelectrochemical transistor (OPECT) bioanalysis. Specifically, Fe/Co‐MIL‐88, serving simultaneously as the semiconductor and nanozyme, was explored as a dual‐functional gating module in OPECT. Upon light illumination, it could accelerate the charge transfer of the photogate to produce enhanced photo‐induced voltage. Meanwhile, its catalytic property could efficiently produce biomimetic precipitation to block the nanopores in Fe/Co‐MIL‐88 and thus alter the device characteristics. The generic bioanalytical potential of such a rationale was then demonstrated with an aptasensing assisted by magnetic separation. This work represents the first exploration of biomimetic precipitation from MOF nanozymes for generic OPECT bioanalysis, it is expected to attract more interest in various nanozymes for novel optoelectronic bioanalytics. [ABSTRACT FROM AUTHOR]

Multi-resonant metasurfaces are of great significance in the applications of multi-band nanophotonics. Here, we propose a novel metasurface design scheme for simultaneously supporting quasi-bound states in continuum (QBIC) and other resonant modes, in which QBIC resonance is generated by mirror or rotational symmetry breaking in oligomers while other resonant modes can be simultaneously excited by rationally designing the shapes of meta-atoms within oligomers. As an example, the simultaneous excitation of QBIC and anapole modes are demonstrated in a dimer metasurface composed of asymmetric dumbbell-shaped apertures. Based on the far-field multipole decomposition and near-field electromagnetic field distributions, the origin mechanisms of QBIC and anapole mode are elucidated. The symmetry breaking of dumbbell-shaped dimer results in QBIC. Within a certain asymmetric variation range, the contributions of toroidal dipole moment and electric dipole moment with approximately equal magnitudes remain dominant, which allows the anapole mode to always present. The effectiveness of the proposed design scheme is further confirmed by the experimental results identical with the evolutions of numerical simulation. In terahertz biosensing experiments, the anapole mode exhibits a higher sensitivity of 271.3 GHz (nmol/μl)−1, whereas the QBIC can achieve a lower detection limit of 0.015 nmol/μl and expands the detection range by almost an order of magnitude. Our findings are beneficial to designing multi-resonant metasurfaces with different resonance modes and promote the corresponding applications in the fields of biosensing, lasers, filtering, and nonlinearity. [ABSTRACT FROM AUTHOR]

Upconversion luminescence (UCL) has great potential for highly sensitive biosensing due to its unique wavelength shift properties. The main limitation of UCL is its low quantum efficiency, which is typically compensated using low-noise detectors and high-intensity excitation. In this work, we demonstrate surface plasmon polariton (SPP)-enhanced UCL for biosensing applications. SPPs are excited by using a gold grating. The gold grating is optimized to match the SPP resonance with the absorption wavelength of upconverting nanoparticles (UCNPs). Functionalized UCNPs conjugated with antibodies are immobilized on the surface of the fabricated gold grating. We achieve an UCL enhancement up to 65 times at low excitation power density. This enhancement results from the increase in the absorption cross section of UCNPs caused by the SPP coupling on the grating surface. Computationally, we investigated a slight quenching effect in the emission process with UCNPs near gold surfaces. The experimental observations were in good agreement with the simulation results. The work enables UCL-based assays with reduced excitation intensity that are needed, for example, in scanning-free imaging. [ABSTRACT FROM AUTHOR]

The enzyme-mimicking nature of versatile nanomaterials proposes a new class of materials categorized as nano-enzymes, ornanozymes. They are artificial enzymes fabricated by functionalizing nanomaterials to generate active sites that can mimic enzyme-like functions. Materials extend from metals and oxides to inorganic nanoparticles possessing intrinsic enzyme-like properties. High cost, low stability, difficulty in separation, reusability, and storage issues of natural enzymes can be well addressed by nanozymes. Since 2007, more than 100 nanozymes have been reported that mimic enzymes like peroxidase, oxidase, catalase, protease, nuclease, hydrolase, superoxide dismutase, etc. In addition, several nanozymes can also exhibit multi-enzyme properties. Vast applications have been reported by exploiting the chemical, optical, and physiochemical properties offered by nanozymes. This review focuses on the reported nanozymes fabricated from a variety of materials along with their enzyme-mimicking activity involving tuning of materials such as metal nanoparticles (NPs), metal-oxide NPs, metal–organic framework (MOF), covalent organic framework (COF), and carbon-based NPs. Furthermore, diverse applications of nanozymes in biomedical research are discussed in detail. [ABSTRACT FROM AUTHOR]

Plasmonic intragap nanostructures (PINs) have garnered intensive attention in Raman-related analysis due to their exceptional ability to enhance light–matter interactions. Although diverse synthetic strategies have been employed to create these nanostructures, the emphasis has largely been on PINs with simple configurations, which often fall short in achieving effective near-field focusing. Three-dimensional (3D) complex PINs, distinguished by their intricate networks of internal gaps and voids, are emerging as superior structures for effective light trapping. These structures facilitate the generation of hot spots and hot zones that are essential for enhanced near-field focusing. Nevertheless, the synthesis techniques for these complex structures and their specific impacts on near-field focusing are not well-documented. This review discusses the recent advancements in the synthesis of 3D complex PINs and their applications in surface-enhanced Raman scattering (SERS). We begin by describing the foundational methods for fabricating simple PINs, followed by a discussion on the rational design strategies aimed at developing 3D complex PINs with superior near-field focusing capabilities. We also evaluate the SERS performance of various 3D complex PINs, emphasizing their advanced sensing capabilities. Lastly, we explore the future perspective of 3D complex PINs in SERS applications. [ABSTRACT FROM AUTHOR]

In present work, synthesis of a nanohybrid material using Fe and MoS2 has been performed via a cost‐effective and environmentally friendly route for sustainable manufacturing innovation. Rice straw extract was prepared and used as a reducing and chelating agent to synthesize the nanohybrid material by mixing it with molybdenum disulfide (MoS2) and ferric nitrate [Fe (NO3)3.9H2O], followed by heating and calcination. The X‐ray diffraction (XRD) pattern confirms the formation of a nanohybrid consisting of monoclinic Fe2(MoO4)3, cubic Fe2.957O4, and orthorhombic FeS with 86% consisting of Fe2(MoO4)3. The properties were analyzed through Fourier‐transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of the dynamic light scattering (DLS) study revealed a heterogeneous size distribution, with an average particle size of 48.42 nm for 18% of particles and 384.54 nm for 82% of particles. Additionally, the zeta potential was measured to be −18.88 mV, suggesting moderate stability. X‐ray photoelectron spectroscopy (XPS) results confirmed the presence of both Fe2+ and Fe3+ oxidation states along with the presence of Molybdenum (Mo), oxygen (O), and Sulphur (S). The prepared nanohybrid material exhibited a band gap of 2.95 eV, and the photoluminescence intensity increased almost twice that of bare MoS2. The present work holds potential applications in photo luminescent nanoplatform for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract In the in vitro motility assay (IVMA), actin filaments are observed while propelled by surface-adsorbed myosin motor fragments such as heavy meromyosin (HMM). In addition to fundamental studies, the IVMA is the basis for a range of lab-on-a-chip applications, e.g. transport of cargoes in nanofabricated channels in nanoseparation/biosensing or the solution of combinatorial mathematical problems in network-based biocomputation. In these applications, prolonged myosin function is critical as is the potential to repeatedly exchange experimental solutions without functional deterioration. We here elucidate key factors of importance in these regards. Our findings support a hypothesis that early deterioration in the IVMA is primarily due to oxygen entrance into in vitro motility assay flow cells. In the presence of a typically used oxygen scavenger mixture (glucose oxidase, glucose, and catalase), this leads to pH reduction by a glucose oxidase-catalyzed reaction between glucose and oxygen but also contributes to functional deterioration by other mechanisms. Our studies further demonstrate challenges associated with evaporation and loss of actin filaments with time. However, over 8 h at 21–26 °C, there is no significant surface desorption or denaturation of HMM if solutions are exchanged manually every 30 min. We arrive at an optimized protocol with repeated exchange of carefully degassed assay solution of 45 mM ionic strength, at 30 min intervals. This is sufficient to maintain the high-quality function in an IVMA over 8 h at 21–26 °C, provided that fresh actin filaments are re-supplied in connection with each assay solution exchange. Finally, we demonstrate adaptation to a microfluidic platform and identify challenges that remain to be solved for real lab-on-a-chip applications.

The development and assessment of pharmaceutical dosage forms make considerable use of gamma-scintigraphy. Gamma scintigraphy is an imaging technique that is integrated with CT to assess and evaluate the targeting of drugs to various delivery sites, the impact of treatment, and the severity of the disease. A small number of radioisotopes were tagged with the delivery system and emitted radiation can be visualized by the gamma camera which forms a 2-D image displaying the tissue-specific distribution of radioactivity. The isotopes that are used widely include Technetium-99 m (99Tc), Iodine (131I), Fluorodeoxyglucose (18F-FDG), Fluoromisonidazole (18F-FMISO) and Gallium (Ga67), Indium (111In). This review mainly covers different applications of gamma scintigraphy for the assessment of drug targeting via different routes to different organs and their visualization by gamma scintigraphy. The review mainly focuses assessment of drug targeting in the tumor tissue, thyroid gland, brain, pulmonary pathway, skin deposition, detection of renal impairment as well as cardiac diseases, drug release from formulations, drug deposition in arthritis, drug retention in the scalp, and behavior of formulation when administered via intra-vaginal route. Various pre-clinical and clinical studies were included in the review that demonstrates the importance and future of gamma scintigraphy in sensing drug delivery.

Highlights Proposed a new paradigm for nanoantenna design using coupled-mode theory. Designed an OC-Hµ resonator with excellent sensing performance. Using OC-Hµ resonators for biomolecule recognition and detection.

MoS2 is a substance, highly valued for its two-dimensional nanostructure and diverse physical and chemical properties. This review examines the advancements achieved in biomedical applications through the integration of molybdenum disulfide (MoS2), and the state-of-the-art area of 3D printing technology. It initially outlines MoS2 synthesis routes and techniques to tailor its properties. The review explores how MoS2 properties underpin its biological significance, thereby facilitating its therapeutic, tissue engineering, and biosensing applications. Emphasis is placed on the emerging area of 3D printing, assessing its potential when combined with MoS2 to produce customized materials for biomedical purposes. Strategies to create foam topologies and electrocatalytically active filaments in 3D-printed constructs are explained. The enhanced mechanical strength, conductivity, and therapeutic efficacy observed in 3D-printed MoS2 structures foreshadow new developments in healthcare, including the advent of biocompatible implants for regenerative medicine and tissue engineering. Further results show how innovations have been made in biosensing areas leveraging MoS2 3D printing. These insights, grounded in scientific research, medical practices, and technological advancements, position MoS2 as a flexible and innovative material with diverse applications across various biomedical sectors.

Silver nanoparticles are among the most widely researched and used for nanotechnology-derived structures due to their extraordinary inherent optical properties, chemical stability, catalytic activity, and high conductivity. These idiosyncratic properties can be attributed to their unique physico-chemical characteristics, such as ultrafine sizes, high surface area, diverse shapes, and strong localized surface plasmon resonance. These distinctive features can be tailored using various physical, chemical, and biological synthesis methods. Various physical techniques are viable for producing silver nanoparticles on a large scale, but they suffer from drawbacks such as high-power consumption, expensive set-up, and limited control over nanoparticle size distribution. Chemical methods provide benefits like high yield, consistent shape and size distribution, and cost efficiency, but the residual toxicity of the chemicals involved hinders their biological applications. Biological synthesis approaches effectively overcome the limitations of both physical and chemical methods by eliminating the need for hazardous chemicals, requiring less energy, enabling diverse nanoparticle morphologies, and offering eco-friendliness and exceptional biocompatibility. The novel and promising properties of nanosilver-based biomaterials have been demonstrated to be suitable for a wide range of pharmacological and therapeutic biomedical applications. Their extensive application in wound healing, dentistry, cardiovascular disease treatment, nerve tissue engineering, cancer treatment, and biosensing can be attributed to their inherent antimicrobial and antibiofilm activity, antithrombotic properties, potential for nerve regeneration, photothermal conversion efficiency and sensitivity, respectively. This review discusses the different methods employed for synthesising silver nanoparticles and focuses on using nanosilver-based biomaterials for various biomedical applications.

Developing a simple and highly sensitive approach for Pseudomonas aeruginosa (P. aeruginosa) detection is crucial, as it is closely associated with various disorders, such as newborn infections. Nevertheless, few of techniques have the capability to accurately identify P. aeruginosa with a high level of sensitivity and significantly improved stability. The employment of the both-end blocked peroxidase-mimicking DNAzyme significantly diminished the interferences from background signals, so conferring the approach with a high degree of selectivity and reproducibility. The proposed method is demonstrated with exceptional discernment capacity in differentiating interfering microorganisms. The simplicity, elevated sensitivity and high discerning capability make the method a highly promising alternative instrument for pathogenic bacteria detection.

Abstract Extracellular vesicles (EVs) harbor several signaling molecules to maintain intercellular communication. Based on the exosomal cargo type, metabolic, genomic, and proteomic status of parent cells can be investigated. Due to the existence of trivial levels of target molecules inside EVs, the application of accurate and sensitive detection methods is mandatory. Here, we used an electrochemical immunosensor using a biotinylated monoclonal CD63 antibody as the capturing element for the detection of EVs isolated from MDA-MB-231 cells and cancer patients. Simultaneously, breast cancer biomarker CA-15-3 was detected in isolated EVs using a sandwich method to increase specificity. Data indicated a linear dynamic range of 2000–10000 EVs/µL and a lower limit of quantification of 2000 EVs/µL. Based on data from real sample analysis, the levels of exosomal CA-15-3 can differ according to the severity and systemic content of this factor. Pd-perovskite-based immunosensor provides a platform for quick and in-depth analysis of EVs isolated for cancer cells.

Abstract Comprehending digital content written in natural language online is vital for many aspects of life, including learning, professional tasks, and decision-making. However, facing comprehension difficulties can have negative consequences for learning outcomes, critical thinking skills, decision-making, error rate, and productivity. This paper introduces an innovative approach to predict comprehension difficulties at the local content level (e.g., paragraphs). Using affordable wearable devices, we acquire physiological responses non-intrusively from the autonomous nervous system, specifically pulse rate variability, and electrodermal activity. Additionally, we integrate data from a cost-effective eye-tracker. Our machine learning algorithms identify ’hotspots’ within the content and regions corresponding to a high cognitive load. These hotspots represent real-time predictors of comprehension difficulties. By integrating physiological data with contextual information (such as the levels of experience of individuals), our approach achieves an accuracy of 72.11% ± 2.21, a precision of 0.77, a recall of 0.70, and an f1 score of 0.73. This study opens possibilities for developing intelligent, cognitive-aware interfaces. Such interfaces can provide immediate contextual support, mitigating comprehension challenges within content. Whether through translation, content generation, or content summarization using available Large Language Models, this approach has the potential to enhance language comprehension.

The functional integration of biological switches with synthetic building blocks enables the design of modular, stimulus‐responsive biohybrid materials. By connecting the individual modules via diffusible signals, information‐processing circuits can be designed. Such systems are, however, mostly limited to respond to either small molecules, proteins, or optical input thus limiting the sensing and application scope of the material circuits. Here, a highly modular biohybrid material is design based on CRISPR/Cas13a to translate arbitrary single‐stranded RNAs into a biomolecular material response. This system exemplified by the development of a cascade of communicating materials that can detect the tumor biomarker microRNA miR19b in patient samples or sequences specific for SARS‐CoV. Specificity of the system is further demonstrated by discriminating between input miRNA sequences with single‐nucleotide differences. To quantitatively understand information processing in the materials cascade, a mathematical model is developed. The model is used to guide systems design for enhancing signal amplification functionality of the overall materials system. The newly designed modular materials can be used to interface desired RNA input with stimulus‐responsive and information‐processing materials for building point‐of‐care suitable sensors as well as multi‐input diagnostic systems with integrated data processing and interpretation. [ABSTRACT FROM AUTHOR]

Glutamate is one of the most important excitatory neurotransmitters within the mammalian central nervous system. The role of glutamate in regulating neural network signaling transmission through both synaptic and extra‐synaptic paths highlights the importance of the real‐time and continuous monitoring of its concentration and dynamics in living organisms. Progresses in multidisciplinary research have promoted the development of electrochemical glutamate sensors through the co‐design of materials, interfaces, electronic devices, and integrated systems. This review summarizes recent works reporting various electrochemical sensor designs and their applicability as miniaturized neural probes to in vivo sensing within biological environments. We start with an overview of the role and physiological significance of glutamate, the metabolic routes, and its presence in various bodily fluids. Next, we discuss the design principles, commonly employed validation models/protocols, and successful demonstrations of multifunctional, compact, and bio‐integrated devices in animal models. The final section provides an outlook on the development of the next generation glutamate sensors for neuroscience and neuroengineering, with the aim of offering practical guidance for future research. [ABSTRACT FROM AUTHOR]

The peroxidase (POD)‐mimic nanozymes can be a potential tool for point‐of‐care (POC) diseases diagnosis. However, the complex sample matrix and unspecific multiple‐enzyme activities of nanozyme can generate false background signal and decrease the diagnostic accuracy. Here, a magnetic and POD‐specific covalent organic framework (COF) confined osmium (Os) nanoclusterzyme Fe3O4@COF@Os is developed for biomarkers biosensing. First, found that the catalytic activity and specificity of Fe3O4@COF@Os can be regulated by the deoxidizers and the functional groups of COF ligands. By using ascorbic acid as deoxidizer and F functional COF ligands, Fe3O4@COF@Os displayed superior POD‐specific activity and negligible oxidase (OXD) and catalase (CAT) mimic activity. Therefore, Fe3O4@COF@Os can separate and analyze of targets in bio‐matrix without background interference. For application, Fe3O4@COF@Os based lateral flow assay is established for serum cancer biomarker prostate‐specific antigen, the detection limit is 3.83 pg mL−1. For clinical prostatic cancer samples, the accuracy is 100% with a correlation coefficient of 0.998 with commercial ELISA kit. For chronic disease biomarker sensing, salivary glucose can be quantified as low as 0.1 µm, with negligible background interference and favorable recyclability. This specific magnetic nanozymes can offer a promising pretreatment‐free and POC strategy for rapid and accurate diseases diagnosis. [ABSTRACT FROM AUTHOR]

All‐dielectric metasurfaces supporting high‐Q resonances have emerged as a promising platform for sensing applications. However, the greatly enhanced near‐fields are usually confined within the all‐dielectric nanostructures rather than the outside analyte region, severely limiting the bulk sensitivity and the biosensing performance. Here, a silicon metasurface formed by the hybridization of two lattices with a relative displacement is designed to support nonlocal quasi‐bound states in the continuum (q‐BICs) featuring homogeneous and significant near‐field enhancement over large volumes outside the silicon nanodisks. A high bulk sensitivity of 407 nm RIU–1 is experimentally demonstrated for the refractive index sensing applications, and a limit of detection down to 20 pg mL–1 for a protein biomarker for the early‐stage breast cancer screening, which is improved by more than an order of magnitude over the state of the art. It is expected that the nonlocal q‐BICs open new opportunities for realizing greatly enhanced light–matter interactions over large volumes in applications beyond biochemical sensing. [ABSTRACT FROM AUTHOR]

Although batteries are a highly popular energy source in biosensors, batteries can be an economic limitation for low‐cost sensing applications and pose significant challenges in miniaturization, biocompatibility, and disposal. To surmount such issues, "self‐powered sensors" gain the spotlight thanks to their energy harvesting from the environment through embedded miniaturized systems. In this review, the recent developments in self‐powered devices are summarized with a specific focus on the integration of supercapacitors with sensors and biosensors. The working principles of microsupercapacitors, fabrication methods, their integration with biosensors, and their ultimate applications (i.e., biomedical monitoring and analytical biomarker detection) are described. Different energy harvesting systems are summarized and their integration with self‐powered sensors or biosensors is highlighted. The limitations and challenges of the existing approaches and the future of supercapacitor‐integrated sensing systems are also critically discussed. [ABSTRACT FROM AUTHOR]

Nucleic acids have the ability to generate advanced nanostructures in a controlled manner and can interact with target sequences or molecules with high affinity and selectivity. For this reason, they have applications in a variety of nanotechnology applications, from highly specific sensors to smart nanomachines and even in other applications such as enantioselective catalysis or drug delivery systems. However, a common disadvantage is the use of water as the ubiquitous solvent. The use of nucleic acids in non-aqueous solvents offers the opportunity to create a completely new toolbox with unprecedented degrees of freedom. Ionic liquids (ILs) and deep eutectic solvents (DESs) are the most promising alternative solvents due to their unique electrolyte and solvent roles, as well as their ability to maintain the stability and functionality of nucleic acids. This review aims to be a comprehensive, critical, and accessible evaluation of how much this goal has been achieved and what are the most critical parameters for accomplishing a breakthrough. [ABSTRACT FROM AUTHOR]

Biosensors in the Terahertz (THz) region are attracting significant attention in the biomedical and chemical analysis fields owing to their potential for ultra-trace sensing of various solutions with high sensitivity. However, the development of compact, highly sensitive chips and methods for easy, rapid, and trace-amount measurements have been significantly hindered by the limited spatial resolution of THz waves and their strong absorption by water. In this study, we developed a nonlinear optical crystal (NLOC)-based compact THz sensor chip, and a near-field point THz source with a diameter of ~ϕ20 μm was locally generated via optical rectification. Here, only the single central meta-atom was excited. The reflective resonance responses highly depend on the array number and period of the meta-atom structures. The sensing performance was examined with several liquid biological samples, such as mineral water, DNA, and human blood. 1 μL of samples was directly dropped onto the meta-surface with an effective sensing area of 0.32 mm2 (564 μm × 564 μm). Obvious resonance frequency shifts were clearly observed. This research holds significance in advancing liquid bio-sample sensing methodologies by facilitating easy, rapid, and trace-amount measurements and promoting the development of compact and highly sensitive THz sensors tailored for liquid biological samples. [ABSTRACT FROM AUTHOR]

Nanocellulose (NC)/graphene oxide (GO) composites are attractive materials with a range of unique features obtained from the integration of NC and GO. These materials have high potential use in various sectors such as biomedicine, wastewater remediation, sensor/biosensor technology, and energy storage/conversion. The simple functionalization and modification of NC or GO afford an opportunity for tailoring these materials for anticipated applications. In wastewater treatment applications, they can be employed as reliable adsorbents for the removal of different pollutants, such as metals, dyes, oils, and pesticides as well as sensors for the detection and monitoring of these pollutants. Besides that, NC/GO composites can be applied as catalysts for catalytic degradation for a wide variety of pollutants. These materials have been also reported to be applicable in biomedical applications such as drug delivery, antibacterial and biosensing. Energy storage applications such as supercapacitors NC/GO-based materials were also utilized. This review summarizes NC/GO hybrid fabrication, characterization, and their application in different fields, i.e. sensing, energy storage, and wastewater remediation. It also covered a broad overview of the status of integrating GO with nanocellulose materials, i.e. bacterial cellulose, cellulose nanofibrils, and cellulose nanocrystals. We concluded with the challenges and outlook for NC/GO-based composites. [ABSTRACT FROM AUTHOR]

Nowadays, coinage metal nanoclusters (NCs) are largely presented in diagnostics, bioimaging, and biocatalysis due to their high biocompatibility, chemical stability, and sensitivity to surrounding biomolecules. Silver and gold NCs are usually characterized by intense luminescence and photostability, which is in great demand in the detection of organic compounds, ions, pH, temperature, etc. The experimental synthesis of metal NCs often occurs on biopolymer templates, mostly DNA and proteins. However, this review mainly focuses on the interactions with small biomolecules (SBMs) of a molecular weight less than 1000 Da: amino acids, nucleobases, thiolates, oligopeptides, etc. Such molecules can serve as the templates for an eco-friendly facile one-pot synthesis of biocompatible luminescent NCs. The latter aspect makes NCs suitable for diagnostics and intracellular bioimaging. Another important aspect is the interaction of clusters with biomarkers, which is largely exploited by nanosensors: biomarker detection often occurs through either fluorescence emission "turn-on" or "turn-off" mechanisms. Moreover, as theoretical studies show, electronic absorption spectra and Raman spectra of the metal-organic complexes allow efficient detection of various analytes. In this regard, both theoretical and experimental studies of SBM complexes with metal NCs are in great demand. Therefore, this review aims to summarize up-to-date studies on the interaction of small biomolecules with coinage metal NCs from both theoretical and experimental viewpoints. [ABSTRACT FROM AUTHOR]

Bioluminescence, the light produced by biochemical reactions involving luciferases in living organisms, has been extensively investigated for various applications. It has attracted particular interest as an internal light source for theranostic applications due to its safe and efficient characteristics that overcome the limited penetration of conventional external light sources. Recent advancements in protein engineering technologies and protein delivery platforms have expanded the application of bioluminescence to a wide range of theranostic areas, including bioimaging, biosensing, photodynamic therapy, and optogenetics. This comprehensive review presents the fundamental concepts of bioluminescence and explores its recent applications across diverse fields. Moreover, it discusses future research directions based on the current status of bioluminescent systems for further expansion of their potential. [ABSTRACT FROM AUTHOR]

The majority of the cell wall of a plant is composed of cellulose. Cellulose is an outstanding abundant, fibrous, and water-insoluble polymer on earth. The excellent hierarchical structure and semicrystalline nature of plant cellulose permit the easy isolation of nanofibers and nanocrystals through mechanically and chemically applied top-down destruction strategies. The cellulose molecules in nanocomposites can be separated into types such as bacterial nanocellulose (BNC), crystalline nanocellulose (CNC), and cellulose nanofibrils (CNF), which are biodegradable, environmentally friendly, and possess remarkably improved properties compared to conventional materials. Generally, they are deliberated as second-generation renewable resources, which assist as a superior replacement for petroleum-based materials. Research studies on nanocellulose are extensively accelerating due to petroleum-based materials issues like CO2 emissions, plastic based-pollution, and the absence of renewable energy. Research studies regarding these materials are interestingly increasing due to their outstanding properties such as biocompatibility, renewability, higher mechanical and lower density values, while sustainable production still associated with various challenges. Here, we comprehensively review the recent developments in nanocellulose production structural dimensions, properties, and applications, dedicated to drug delivery system, food industry, piezoelectric sensors, actuators, energy generators biosensing and bioimaging electronic devices. [ABSTRACT FROM AUTHOR]

Haptics is a research field related to the sense of touch. When humans perceive vibrations, the magnitude of sensory quantity is determined by the amount of skin displacement. A haptic actuator using mid-air ultrasonic waves is suitable for measuring the skin displacement during tactile presentation because they allow contactless tactile presentation. However, studies that directly observe the amount of skin displacement during the sensing of vibration have been conducted only at a very limited displacement of 3 µm, despite the sensible skin displacement range being approximately 10 mm-0.01 µm. In this study, ultrasonic speakers were used to generate higher sound pressures than conventional ultrasonic speakers to produce large displacements. The goals of this study are to observe the characteristics of skin displacement and to map the amount of displacement to the sensory amount. In this paper, we used a dummy skin instead of a biological skin to investigate the validity of the constructed observation system and the adaptability of the skin viscoelasticity model proposed in the previous study. From the measurement results, obtained at a maximum acoustic radiation pressure of 4000 Pa, a maximum displacement of 170 µm is obtained. This is 50 times larger than that obtained in the previous study. The displacement amount is consistent with the displacement model proposed in the previous study and the elastic modulus obtained from the dynamic viscoelasticity measurement. Furthermore, the simulation results obtained from that model suggest that the displacement characteristics of Asker C15 of HITOHADA® GEL would be similar, suggesting that this HITOHADA® GEL could be used as an alternative material. [ABSTRACT FROM AUTHOR]

Gold nanoclusters (AuNCs) are a class of novel luminescent nanomaterials that exhibit unique properties of ultra-small size, featuring strong anti-photo-bleaching ability, substantial Stokes shift, good biocompatibility, and low toxicity. Various biomolecules have been developed as templates or ligands to protect AuNCs with enhanced stability and luminescent properties for biomedical applications. In this review, the synthesis of AuNCs based on biomolecules including amino acids, peptides, proteins and DNA are summarized. Owing to the advantages of biomolecule-protected AuNCs, they have been employed extensively for diverse applications. The biological applications, particularly in bioimaging, biosensing, disease therapy and biocatalysis have been described in detail herein. Finally, current challenges and future potential prospects of bio-templated AuNCs in biological research are briefly discussed. [ABSTRACT FROM AUTHOR]

The advancement of nanozymes with oxidase-initiating activity that are affordable and stable is essential for real-time monitoring in biosensors, medicine, and environmental protection and remains a significant challenge. Covalent organic framework (COF) is an emerging type of crystalline porous organic framework material that is constructed from organic building units by covalent bonds. In this study, we successfully synthesized three isoreticular two-dimensional (2D) COFs by choosing diarylamino-benzene-based tetra-amines to construct [4 + 4]-type COFs. The resultant COFs exhibited excellent oxidase-mimicking activity under light stimulation, which can catalyze the oxidation of tetramethylbenzydine (TMB) by the formation of O2•– free radicals under an open-air condition. A sensitive sensor was designed based on the oxidase-mimicking activity of these COFs for the determination of glutathione (GSH) in real samples, achieving a detection limit of 0.22 μM, outperforming the standard materials studied in GSH detection within reticular frameworks. This work offers possibilities for investigating the oxidase-initiating activity of nanozymes and broadening the utilization of COFs in the realm of biosensing. [ABSTRACT FROM AUTHOR]

With their regulated Boolean logic operations in vitro and in vivo, DNA logic circuits have shown great promise for target recognition and disease diagnosis. However, significant obstacles must be overcome to improve their operational efficiency and broaden their range of applications. In this study, we propose an Exo III-powered closed-loop DNA circuit (ECDC) architecture that integrates four highly efficient AND logic gates. The ECDC utilizes Exo III as the sole enzyme-activated actuator, simplifying the circuit design and ensuring optimal performance. Moreover, the use of Exo III enables a self-feedback (autocatalytic) mechanism in the dynamic switching between AND logic gates within this circulating logic circuit. After validating the signal flow and examining the impact of each AND logic gate on the regulation of the circuit, we demonstrate the intelligent determination of miR-21 using the carefully designed ECDC architecture in vitro. The proposed ECDC exhibits a linear detection range for miR-21 from 0 to 300 nM, with a limit of detection (LOD) of approximately 0.01 nM, surpassing most reported methods. It also shows excellent selectivity for miR-21 detection and holds potential for identifying and imaging live cancer cells. This study presents a practical and efficient strategy for monitoring various nucleic acid-based biomarkers in vitro and in vivo through specific sequence modifications, offering significant potential for early cancer diagnosis, bioanalysis, and prognostic clinical applications. [ABSTRACT FROM AUTHOR]

Mortality from cardiovascular disease (CVD) accounts for over 30% of all deaths globally, necessitating reliable diagnostic tools. Prompt identification and precise diagnosis are critical for effective personalized treatment. Nanotechnology offers promising applications in diagnostics, biosensing and drug delivery for prevalent cardiovascular diseases. Its integration into cardiovascular care enhances diagnostic accuracy, enabling early intervention and tailored treatment plans. By leveraging nanoscale innovations, healthcare professionals can address the complexities of CVD progression and customize interventions based on individual patient needs. Ongoing advancements in nanotechnology continue to shape the landscape of cardiovascular medicine, offering potential for improved patient outcomes and reduced mortality rates from these pervasive diseases. Article highlights Nanotechnology in early cardiac marker detection Nanoparticles possess a wide range of capabilities for diagnostic purposes, namely in the realm of early identification of atherosclerosis by the quantification of inflammatory markers. Precision and effectiveness are essential for the detection of heart-type fatty acid-binding protein (H-FABP) as an early biomarker for cardiac events. Several techniques, such as chromatography (HPLC, GC-MS) and immunoassays (ELISA, LFIA), can be used with distinct advantages in terms of sensitivity, specificity and turnaround time. Challenges with immunoassays include the occurrence of cross-reactivity and interference, while chromatographic procedures require specialized equipment and skilled personnel. MicroRNAs (miRNAs) control gene expression and exhibit stability in human fluids, rendering them valuable as biomarkers. miRNA-21 is a biomarker that is specifically intriguing for heart failure due to its involvement in both the etiology and diagnostics of the condition. Therapeutic approaches aimed at miRNA-21 entail the use of antagomiRs and miRNA mimics, which present opportunities for precision medicine. miRNA-21 is involved in heart hypertrophy, fibrosis and remodeling, and its abnormal regulation offers diagnostic and prognostic information. Current challenges & limitations in early detection Early diagnosis of heart issues is essential for effective treatment and better outcomes. Advanced cardiac implantable electronic devices (CIEDs) are increasingly employed for congestive heart failure, ventricular tachyarrhythmia and bradyarrhythmia. Regular battery changes remain necessary, despite breakthroughs in battery design and CIED programming, resulting in cost, risk and inconvenience. Transvenous lead extraction for damaged leads is potentially fatal. Spin-echo (SE) sequences, enhanced by ECG-gating, improve myocardial-blood contrast but have limited temporal resolution and motion-related artefacts. Ejection fraction (EF), a typical systolic function measure, is susceptible to inaccuracies due to subjective endocardial boundary tracing. Emerging biochemical diagnostics for heart disease encounter hurdles in standardization, preanalytical variability and imprecision. Reliable economic evaluations of test costs and benefits are lacking. Immunoassays for novel cardiac proteins use antibodies targeting various epitopes, resulting in varying results and interpretation challenges. "Sandwich" immunoassays may produce false positives due to disturbances in antigen-antibody reactions and interference by factors like rheumatoid factor or human antimouse antibodies. The presence of endogenous substances like hemoglobin and bilirubin can lower the sensitivity and specificity of troponin assays. POC devices for cardiac troponins and BNP detection are sensitive yet expensive and time-consuming. Recent advances & innovations in early detection Patenting theranostic nanoparticles, developing a UV-cross-linkable cardiac patch with gold nano-rods and creating nanoparticle-based stem cell conjugates for post-infarction treatment are significant advances in spatially designed nanoparticle trials in CVDs, neurological disorders and cancer therapies. AuNPs and iron oxide nanoparticles improve imaging of atherosclerotic plaques and CVDs, with CNA35-AuNPs found to improve contrast and detection in CT images. MRI, utilizing T2 and T1 mapping, 4D flow imaging and nanoplatforms, enhances imaging accuracy and precision, replacing biopsies for heart structure, function and tissue characteristics. PET imaging in CVDs uses radioactive tracers for 3D imaging of biological processes, such as myocardial perfusion using 13N-ammonia, enhanced by nanoplatforms and targeting ligands improving specificity and effectiveness. Enhanced ultrasound imaging with nanoparticles targeting vascular markers enhances echogenicity and contrast-to-noise ratio, resulting in safe and effective real-time imaging. MSOT and PAI use photoacoustic imaging for high-resolution carotid artery and atherosclerosis detection, with nanoparticles improving sensitivity, contrast and specificity. MPI, a real-time, high-resolution imaging method, enhances signal strength and accuracy with optimized nanoparticles for tracer detection, multiplexed imaging and sensitivity. [ABSTRACT FROM AUTHOR]