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Dopamine is a major catecholamine neuro-transmitter that plays important function in the human central nervous system's function. Dopamine release disorders are linked to neurological illnesses and depression. To comprehend dopamine's physiological roles, it is vital to monitor dopamine levels at early stage or in regular basis. Many diagnostic procedures are accessible, but they have limitations, thus low-cost and simple ways to test dopamine were needed like colorimetric biosensors. Such biosensors were built with nanoparticles (gold) as a label to help identify targets and the results may be viewed with the naked eye. These gold nanomaterials are available in a range of morphologies, including nanoparticles, nanorods, and others. The present method reported the use of gold nanoparticles (GNPs) and gold nanorods (GNRs) for effective aptamer-based sensing of dopamine. Herein a comparison study was conducted between GNPs and GNRs based apta-sensing of dopamine. Both AuNPs (gold nanoparticles) and AuNRs (gold nanorods) were characterised by SEM (Scanning electron microscope), XRD (X-Ray diffraction) and UV-Vis spectrophotometer (Ultraviolet-Visible spectroscopy). The result claimed that GNRs are more sensitive as they were detecting low concentration of dopamine which was confirmed via UV analysis. Various other parameters such as change in salt concentration, incubation time and interferents were also studied which proved that utilising aptamer and gold-nanorods can be a promising material in the neurotransmitter based diagnosis. [ABSTRACT FROM AUTHOR]

In this work, negative-capacitance (NC) and local surface plasmon resonance (LSPR) coupled MoS2 phototransistors with a gate stack of HZO/AuNPs/Al2O3/MoS2 are fabricated, and the impacts of Al2O3 interlayer-thickness (TAlO) on the LSPR effect, the tensile strain on MoS2 from the Au nanoparticles (AuNPs), the capacitance matching of the NC effect from Hf0.5Zr0.5O2 (HZO) ferroelectric layer and the optoelectrical properties of the relevant devices are investigated. Through optimizing TAlO, excellent optoelectrical properties of phototransistors with a TAlO of 3 nm are achieved: a subthreshold swing (SS) of 25.76 mV/dec and ultrahigh detectivity of over 1014 Jones under 740 nm illumination. This is primarily because the NC-LSPR coupled structure can achieve an ultra-low SS through capacitance matching and a good interface passivation through optimizing Al2O3 interlayer to maintain effective LSPR and strain effects cross the MoS2 to enhance optical absorption and detection range. This work provides a comprehensive analysis on effective distance range of the non-direct-contacted LSPR effect and its combination with capacitance matching of NC effect, culminating in an optimized NC-LSPR coupled MoS2 phototransistor with a good consistency across an array of 30 devices, and offering a viable solution for the preparation of large-area, high-performance and broad-spectrum response 2D phototransistor array. [ABSTRACT FROM AUTHOR]

Comprehensive Summary The programmability of DNA assembly allows for the creation of gold nanostructures with custom shapes and tailored optical properties, holding promise for applications including single‐molecule sensing and imaging. While DNA origami provides addressable site information for structure construction, there have been few studies on encoding information onto gold nanoparticles (AuNPs) to guide the assembly of Au‐DNA origami structures, especially for encoding extensive information onto large AuNPs (e.g., 30 nm). In this work, we introduce a strategy that encodes extensive information onto versatile AuNPs ranging in size from 5 nm to 30 nm using a DNA origami template (parent origami). This encoded information serves to direct the positioning of the AuNPs within a regenerated DNA origami structure (daughter origami). Our findings demonstrate the successful assembly of AuNPs ranging from 5 nm to 30 nm on the same site of the daughter DNA origami as the parent DNA origami, with yields of up to 80%. This approach offers new possibilities for achieving precise control over AuNPs assembly and functionality. [ABSTRACT FROM AUTHOR]

C-reactive protein (CRP) is a protein made by the liver, which is released into the bloodstream in response to inflammation. Furthermore, CRP is a potential risk factor for heart disease. Hence, it is of great importance to develop a rapid, sensitive, accurate, and cost-effective method for CRP detection. Herein, we report an enzyme-free fluorescent assay for the rapid and ultra-sensitive detection of CRP with a limit of detection (LOD) reaching as low as 3.08 pg/mL (i.e., ~ 27 fM). The high sensitivity of our method was simply achieved via dual-functionalized gold nanoparticles (AuNPs). By regulating the molar ratio of DNA to CRP antibody immobilized on the AuNP surface, hundreds to thousands-fold amplification in the analyte signal could be instantly accomplished. Furthermore, our sensor was selective: non-target proteins such as interleukin-6, interleukin-1β, procalcitonin, bovine serum albumin, and human serum albumin did not interfere with the target CRP detection. Moreover, simulated serum samples were successfully analyzed. Given the excellent sensitivity, selectivity, and high resistance to complicated matrices, the enzyme-free CRP detection strategy developed in this work can be used as a generic platform to construct sensors for a wide variety of protein biomarkers and hence offers potential as a tool for rapid, accurate, and low-cost medical diagnosis. [ABSTRACT FROM AUTHOR]

Malaria remains one of the causes of extreme mortality in southern Africa and Southeast Asia. Despite extreme efforts to control and eliminate malaria, the appearance of drug-resistant parasites and their spread is a major concern. In this context various therapeutic, diagnostics, and technological advancements need to be studied and implemented in the near future. Nanoparticles have a crucial role in enhancing intracellular retention, subcellular target specificity, and even drug escape from intracellular enzymatic inactivation. Additionally, the selectivity and specificity of anti-malarial against the target were increased by the functionalization of nanoparticles, which led to improved safety and efficacy. Recent studies show the efficacy of metallic nanoparticles against the vector Anopheles mosquito and the malaria parasite Plasmodium species. So, here in the present review, we will discuss the various metal-based nanoparticles that have been studied for malaria treatment or used for the development of detection and diagnosis between the year 2013 and till date. This review also covers the future prospects of these nanoparticles in this field. [ABSTRACT FROM AUTHOR]

The green and eco-friendly synthesis of gold nanoparticles (AuNPs) from renewable resources such as plants, algae, fungi, and bacteria has recently gained interest due to its use of sustainable feedstocks. This review presents an in-depth exploration of AuNP synthesis methods and their applications in cancer imaging and therapy. We examine the mechanisms behind various physical and chemical techniques used to synthesize AuNPs, with a special focus on the unique biomedical applications of green-synthesized AuNPs in diagnostic and therapeutic platforms, such as imaging and targeted therapy. Although promising, green synthesis of AuNPs faces challenges, including variability in particle size, limitations in morphology control, and scalability issues, which need to be addressed to fully harness their potential. This review also demonstrates that AuNPs can be loaded with anticancer agents to create targeted drug delivery vehicles for tumor treatment. As nanotechnology drives revolutionary advances in healthcare, AuNPs offer a promising toolkit for medical progress. However, a fundamental understanding of AuNPs and rigorous risk assessments in diagnostics, imaging, and therapeutic applications are essential to enable their safe and effective use in clinical settings. [ABSTRACT FROM AUTHOR]

Nanothermometry explores the use of temperature‐dependent properties of materials for remote and sensitive thermal readout at the nanoscale. The currently established nanothermometers are largely limited by uncontrollable nanoparticle flocculation, complex experimental setup, and narrow working temperature range. Here it is shown that gold nanoparticles (e.g., spheres, rods) embedded in a hydrogel can afford sensitive, durable, and range‐tunable temperature sensing via the terminal breathing of the nanoparticle surface‐grafted DNA. The realization of the plasmonic hydrogel thermometer with a thermal sensitivity of ≤2 °C relies on the dynamically modulable interparticle spacing by thermo‐responsive terminal base pairing/unpairing of the surface DNA. By altering the alcoholic ratio of the hydrogel, the temperature‐response range can be continuously regulated based on solvent‐mediated DNA base pairing. Compared with the colloidal counterpart, importantly, the hydrogel thermometer exhibits greatly improved thermal sensing capability (e.g., repeatability ≥50 times) while possessing excellent durability. Given the excellent durability, high sensitivity, and programmable temperature response range, the thermometers actuated by DNA breathing for advanced uses in human sensing and optoelectronics are within reach. [ABSTRACT FROM AUTHOR]

The objective of this study was to prepare metallic gold nanoparticles (AuNPs) from the Diospyros kaki L. (persimmon) leaf (DKL) extract, which was grown in the Trabzon province of Türkiye, using microwave extraction. Separate additions of 0.1 and 0.5 mL DKL extract were made to the 0.5 mM HAuCl4.3H2O solution while the heater was kept at 25 °C and stirring continuously. In this method, UV-Vis spectroscopy (300–800 nm) absorption measurements were performed on extracts of Diospyros kaki L. leaves at different time intervals (10, 20, 30, 60, 120, and 1440 min). Green chemistry principles were utilized in the preparation of gold nanoparticles (AuNPs), which were characterized by UV–visible, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and Zetasizer. FTIR analysis can be used to determine the various functional groups that were synthesized in the gold (Au) nanoparticles. Based on the AuNPs' XRD peaks, the average crystallite size was determined to be 25.99 nm. Zetasizer study results showed that the average particle size of Au nanoparticles produced by microwave extraction in an aqueous medium was 45.44 ± 1.095 nm, the zeta potential (ZP) was − 16.9 mV ± 1.19, and the polydispersity index was 0.316 ± 0.009. The UV-Vis absorption spectra of the AuNP solutions were stable for approximately 2.5 to 3 months when they were kept in a refrigerator. [ABSTRACT FROM AUTHOR]

Recent advancements in cancer drug delivery have various drawbacks. To address these constraints, a new paradigm for the creation of AuNPs from microorganisms is being explored due to its cost-effectiveness, mass production capability, and substantial environmental impact. Herein, we described a facile method for biosynthesis of AuNPs employing the radiation-resistant extremophile bacterium Deinococcus radiodurans culture filtrate (cell free supernatant) as a reducing agent and capping agent in an aqueous solution without any external energy. The synthesis of AuNPs was inferred by the color change from pale red to purple that was supported by various characterization tools. The UV–visible spectrum has an absorption peak at 542 nm, which highlights the excitation and Surface Plasmon resonance of AuNPs. The FT-IR was used to examine the functionalization of the biosynthesized AuNPs. The FESEM image of AuNPs are spherical in shape and range in size from 30 to 50 nm and the AuNPs was functionalized with Polyvinylpyrrolidone and further conjugated with the targeting vehicle folate for the delivery of Quercetin. The drug release of Quercetin shows 90 % at 22 hours. Functionalized AuNPs demonstrated dose-dependent cytotoxicity in this investigation against the human breast cancer MCF-7 cell line. Furthermore, the study of apoptotic induction using the AO/EB staining approach demonstrates the obvious morphological alterations brought on by induced apoptosis. Based on the administration of Quercetin, DNA damage has been shown by DNA fragmentation analysis. AuNPs from the culture filtrate of bacterium Deinococcus radiodurans are being actively synthesized and functionalized for a targeted anticancer drug delivery system in the current work. [Display omitted] • Microbial mediated AuNps are synthesized from the bacterium Deinococcus radiodurans. • The particle Size of AuNps ranging from 10 to 50 nm is used for Qur drug delivery. • The Nanocomposite [AuNPs-PVP-FA-Qur] shows an excellent anticancer potential. [ABSTRACT FROM AUTHOR]

Abstract Malaria remains one of the causes of extreme mortality in southern Africa and Southeast Asia. Despite extreme efforts to control and eliminate malaria, the appearance of drug-resistant parasites and their spread is a major concern. In this context various therapeutic, diagnostics, and technological advancements need to be studied and implemented in the near future. Nanoparticles have a crucial role in enhancing intracellular retention, subcellular target specificity, and even drug escape from intracellular enzymatic inactivation. Additionally, the selectivity and specificity of anti-malarial against the target were increased by the functionalization of nanoparticles, which led to improved safety and efficacy. Recent studies show the efficacy of metallic nanoparticles against the vector Anopheles mosquito and the malaria parasite Plasmodium species. So, here in the present review, we will discuss the various metal-based nanoparticles that have been studied for malaria treatment or used for the development of detection and diagnosis between the year 2013 and till date. This review also covers the future prospects of these nanoparticles in this field.

In this work, negative-capacitance (NC) and local surface plasmon resonance (LSPR) coupled MoS2 phototransistors with a gate stack of HZO/AuNPs/Al2O3/MoS2 are fabricated, and the impacts of Al2O3 interlayer-thickness (T AlO) on the LSPR effect, the tensile strain on MoS2 from the Au nanoparticles (AuNPs), the capacitance matching of the NC effect from Hf0.5Zr0.5O2 (HZO) ferroelectric layer and the optoelectrical properties of the relevant devices are investigated. Through optimizing T AlO, excellent optoelectrical properties of phototransistors with a T AlO of 3 nm are achieved: a subthreshold swing (SS) of 25.76 mV/dec and ultrahigh detectivity of over 1014 Jones under 740 nm illumination. This is primarily because the NC-LSPR coupled structure can achieve an ultra-low SS through capacitance matching and a good interface passivation through optimizing Al2O3 interlayer to maintain effective LSPR and strain effects cross the MoS2 to enhance optical absorption and detection range. This work provides a comprehensive analysis on effective distance range of the non-direct-contacted LSPR effect and its combination with capacitance matching of NC effect, culminating in an optimized NC-LSPR coupled MoS2 phototransistor with a good consistency across an array of 30 devices, and offering a viable solution for the preparation of large-area, high-performance and broad-spectrum response 2D phototransistor array.

Detecting glucose accurately and sensitively from clinical samples like tears and saliva is still difficult. We have created a sensor that can detect glucose with high sensitivity and accuracy by combining the use of glucose oxidase (GOx) to catalyze glucose, a pistol-like DNAzyme (PLDz) to transform the signal, gold nanoparticles (AuNPs) to enhance the optical properties and the exonuclease-III (Exo-III) to amplify the signal. As a result, the proposed method exhibits a low detection limit of 7.5 pM and a wide detection range covering seven orders of magnitude. The suggested dual-mode strategy provides a sensitive, precise and specific detection method for glucose. Another advantage is that the dual-mode technique significantly improves the precision and consistency of the measurements, demonstrating its immense potential for use in biomedical research and clinical diagnostics.

Abstract Background Morphine serves as a foundation for creating other opioid derivatives, such as hydro/oxymorphine and heroin, which possess enhanced pain-relieving properties but are also prone to addiction and abuse. In cases of morphine overdose, it not only affects multiple immune functions but can also cause severe health complications. Given these concerns and the widespread use of morphine, it is crucial to develop efficient, uncomplicated, and precise methods for accurately detecting morphine in various biological and pharmaceutical samples. Results In this investigation, a novel gold nanoparticle (AuNPs)-based double network hydrogel (DNH) nanoprobe has been fabricated for sensitive quantification of morphine in exhaled breath condensate samples. For that, gelatin/agarose DNH was fabricated through a one-step heating-cooling method in the presence of AuNPs, providing not only chemical stability but also prevent the AuNPs aggregation during synthesis process. In this method, the absorbance intensity of the nanoprobe gradually decreased with increasing morphine concentration due to the interaction morphine with AuNPs surface plasmon. The aggregation of AuNPs by addition of morphine was verified by UV-Vis spectrophotometry. The sensor displayed high sensitivity with detection limit of 0.006 µg.mL-1 in the linear range from 0.01 to 1.0 µg.mL-1. A reliable performance was attained for the spectrophotometric method for determination of morphine in the real samples.

Background: Morphine serves as a foundation for creating other opioid derivatives, such as hydro/oxymorphine and heroin, which possess enhanced pain-relieving properties but are also prone to addiction and abuse. In cases of morphine overdose, it not only affects multiple immune functions but can also cause severe health complications. Given these concerns and the widespread use of morphine, it is crucial to develop efficient, uncomplicated, and precise methods for accurately detecting morphine in various biological and pharmaceutical samples. Results: In this investigation, a novel gold nanoparticle (AuNPs)-based double network hydrogel (DNH) nanoprobe has been fabricated for sensitive quantification of morphine in exhaled breath condensate samples. For that, gelatin/agarose DNH was fabricated through a one-step heating-cooling method in the presence of AuNPs, providing not only chemical stability but also prevent the AuNPs aggregation during synthesis process. In this method, the absorbance intensity of the nanoprobe gradually decreased with increasing morphine concentration due to the interaction morphine with AuNPs surface plasmon. The aggregation of AuNPs by addition of morphine was verified by UV-Vis spectrophotometry. The sensor displayed high sensitivity with detection limit of 0.006 µg.mL-1 in the linear range from 0.01 to 1.0 µg.mL-1. A reliable performance was attained for the spectrophotometric method for determination of morphine in the real samples. Significance: This article has reported a new advanced optical scaffold based on double network polymeric hybrid hydrogel for the determination of morphine. This is first report of using such composite for determination of opioids in exhaled breath condensate samples. [ABSTRACT FROM AUTHOR]

Calcium ions (Ca2+) are essential for a myriad of physiological functions, including excitability, neurotransmitter release, gene transcription, cell proliferation, synaptic plasticity, and hormone secretion. Consequently, the detection of Ca2+ concentrations in water is of fundamental and practical significance. In this study, a novel method for the simple, visual, and rapid colorimetric detection of Ca2+ is introduced, leveraging the surface plasmon resonance (SPR) absorbances of gold nanoparticles (AuNPs) modified with 5‐Pyrimidinylboronic acid (5‐PBA). A color change from wine‐red to gray‐blue was observed with increasing concentrations of Ca2+, indicative of the agglomeration of AuNPs. This agglomeration displayed favorable anti‐interference properties and selectivity. The limits of detection (LOD) were determined to be 0.08 mM by the unaided eye and 3.29 μM by UV‐visible spectroscopy. Moreover, an excellent linear relationship (R2=0.9879) was maintained within the Ca2+ concentration range of 0.0 to 0.5 mM. These results suggest that AuNPs modified with 5‐PBA are suitable for the quantitative determination of Ca2+. Subsequent testing on actual samples confirmed that this new method could be effectively applied to the monitoring of Ca2+ in water. [ABSTRACT FROM AUTHOR]

In this study, we present the synthesis of gold nanoparticles (AuNPs) using a completely green synthesis method without the use of any additional functionalizing agent, except dried turmeric root extract. The significant synthesis parameters were optimized, and the applicability of AuNPs was investigated in areas such as plasmonic and fluorescent sensing of aluminum (Al3⁺) and chromium (Cr3⁺) ions, reduction of 4-nitrophenol (4-NP), and degradation of methylene blue (MB) and methyl orange (MO) dyes. Characterization studies were performed using UV–Vis spectroscopy, TEM, FTIR, and XRD, revealing that the AuNPs predominantly had a spherical morphology and a very small particle size of 8.5 nm, with stability maintained up to 120 days. The developed AuNP-based plasmonic sensors relied on aggregation-induced decreases in absorption, along with a red shift in the spectra. Fluorescence sensing demonstrated a linear increase in intensity with increasing concentrations of Al3⁺ and Cr3⁺, with detection limits of 0.83 and 1.19 nM, respectively. The catalytic activities of AuNPs were tested in reducing 4-NP and degradations of MB and MO dyes (binary system) in tap water and wastewater, with the reactions following pseudo-first-order kinetics. This study highlights the potential of AuNPs synthesized from turmeric roots for various environmental and sensing applications. [ABSTRACT FROM AUTHOR]

Food safety control is a key issue in the food and agriculture industries. For such purposes, developing miniaturized analytical methods is critical for enabling the rapid and sensitive detection of food supplements, allergens, and pollutants. Here, a novel bioanalytical methodology based on DNA-functionalized gold nanoparticles (AuNPs) and colorimetric detection was developed to detect the presence of sesame (a major allergen) through sesame seed DNA as a target, in food samples. The presence of sesame DNA induces controlled nanoparticle aggregation/desegregation, resulting in a color change (from blue to red) proportional to sesame DNA concentration. The incorporation of multicomponent nucleic acid enzymes (MNAzymes) in this strategy has been carried out to perform an isothermal signal amplification strategy to improve the sensitivity of detection. Also, open-source software for color analysis was used to ensure an unbiased visual color-change detection, enhancing detection accuracy and sensitivity and opening the possibility of performing a simple and decentralized analyte detection. The method successfully detected the presence of sesame DNA in sesame seed, sesame oil, olive oil, and sunflower oil. In brief, the developed approach constitutes a simple and affordable alternative to perform a highly sensitive detection of DNA in food without complex methodologies or the requirement of expensive instrumentation. [ABSTRACT FROM AUTHOR]

This paper reports white solid-state lighting potential of gold nanoparticles-embedded Dy3+-doped Li2CO3–SrO–ZnO–B2O3 glasses prepared using melt quenching. The produced materials undergo characterizations using various instrumentations to assess the sensitivity of changing AuNP concentrations on their emission characteristics. XRD phase analysis established that the samples were glasses. TEM analysis shows AuNPs, whereas EDX spectroscopic analysis confirmed the inclusion of precursor elements into the glasses. The thermal stability, Hruby parameter, and glass-forming ability are 146–156 °C, 1.27–1.39 and 66–0.65 respectively. The optical absorption spectra of the glasses are consistent with Dy3+ transitions, while the surface plasmon resonance band fits the AuNPs characteristics band. The emission spectroscopic analysis reveals intensification factors of 1.52, 1.84, and 1.14 for 6H15/2, 6H13/2, and 6H11/2 transitions. The Judd–Ofelt evaluation was made to support the experimental spectroscopic data. The CIE coordinates were traced to cool white color field with purity of 15.64–7.79% and CCT values of 5491–5437 K. The achieved excellent thermal properties, enhanced emission, and colorimetric properties, including color purity and natural daylight (cool) correlated color temperature (CCT) values, are advantageous for white solid-state lighting applications. [ABSTRACT FROM AUTHOR]

The green route of transition metal nanoparticle (NPs) synthesis by the single-step method has more attraction for multifunctional applications. The study aimed to demonstrate the use of Pandanuscanaranus leaf extract, as an apposite substrate for the bio-synthesis of silver (Ag) NPs and Gold (Au) NPs. The UV–Vis spectrum of AgNPs and AuNPs showed an absorption peak at 450 and 520 nm, respectively. FT-IR revealed the respective functional groups (carboxylic acids and phenols) involved in the reduction of Ag + and Au + ions to nanoparticles. The XRD findings confirmed the crystalline nature of Ag and AuNPs with face-centered cubic structures, respectively. SEM images showed spherical and agglomerated morphology. Furthermore, EDX results confirmed the presence of Ag and Au metals. HRTEM images determined the sizes of AgNPs (6.33 to 24.43 nm) and AuNPs (37.44 nm) with spherical morphology. High hatching efficiency and less mortality of Artemia salina nauplii were observed in the treatment of AuNPs (93% and 26%) than AgNPs (91 and 55%). As the concentration of AgNPs and AuNPs increased, the findings of cell viability reduced (36 and 50%) in the lung cancer cells (A549 cells), respectively. The early and late apoptosis induced by the NPs in A549 cells were evidenced through AO/EtBr staining. To sum up, the PCLE-mediated NPs synthesis was very rapid and they significantly induced the apoptosis in A549 cells. With these promising potentials, P.canaranus can progress as a good candidate for cancer therapy. [ABSTRACT FROM AUTHOR]

Miniaturization to nano-sized structures is recently described as the most extensively considered trend in science and industry. This field of research also holds immense potentiality for the application in textile industry. Various techniques are recently shown to be available and can be applied to produce uniform film of functional moieties to be uploaded within the textile matrix to acquire the finished fabrics special functionalities that are hitherto unknown in textile industrialization. Herein, unique methodology is demonstrated for functional finishing of wool via self-nucleation of metal nanoparticles (MNPs) especially gold and palladium nanoparticles (AuNPs and PdNPs). MNPs were in situ clustered within native wool using two different concentrations (100 and 300 ppm). Mean size of palladium in the supernatants was evaluated via transmission electron microscopic images to be 8.8 ± 4.0 and 7.1 ± 3.2 nm, for 100 ppm and 300 ppm, respectively. Whereas, in case of gold in the supernatants, mean size was estimated to be 30.3 ± 6.5 and 29.7 ± 10.9 nm, for 100 ppm and 300 ppm, respectively. The yellowness index was observably raised from 15.67 for wool finished with 300 ppm of AuNPs to 74.99 for wool finished with the same concentration of PdNPs. Functional fishing of wool with higher concentration of AuNPs exhibited the highest antimicrobial performance compared to the other tested samples, whereas, after five washings, the microbial reduction percent was estimated. Ultraviolet protection was superiorly improved with in situ nucleation of MNPs. In summarization, it could be decided that the currently designed technique could be promisingly applied for the preparation of highly durable functional wool fabrics. [ABSTRACT FROM AUTHOR]

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The research proposes and investigates an extraordinarily sensitive, label-free WaveFlex biosensor utilizing optical fiber technology for the detection of Staphylococcus aureus (S. aureus), a common foodborne bacterium. The WaveFlex biosensor (plasmon Wave based Flexible optical fiber Biosensor) is based on a novel flexible tapered single-mode fiber structure, utilizing gold nanoparticles (AuNPs) to trigger the phenomenon of localized surface plasmon resonance (LSPR). Additionally, the sensitivity is further enhanced using chitosan-coated iron(III) oxide nanoparticles (Fe3O4–CS NPs) and tungsten disulfide quantum dots (WS2-QDs). The optical fiber surface is functionalized with antibodies to achieve specific detection of S. aureus. For S. aureus concentrations at 1 × 108 CFU/mL (colony-forming units per milliliter), the sensor's maximum sensitivity of 2.74 nm/lg (CFU/mL), and a detection limit (LOD) of 6.67 CFU/mL. This ultra-sensitive biosensor holds great potential for widespread applications in various fields, including disease detection, medical diagnostics, and food safety inspection.

ABSTRACTThe severe threat of microbial contamination to human life and health safety necessitates urgent research and development of antimicrobial materials capable of inhibiting or eradicating pathogens. Cyclodextrin metal-organic framework (CD-MOF) was utilized as a carrier to encapsulate gold nanoparticles (AuNPs), resulting in a composite material (Au@CD-MOF) that exhibited remarkable antibacterial properties. The antibacterial study revealed that Au@CD-MOF completely eradicated Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes) at a concentration of approximately 1 × 105 CFU/mL after 48 h and 36 h, respectively. Moreover, Au@CD-MOF also demonstrated the complete elimination of Escherichia coli O157:H7 (E. coli O157:H7), Pseudomonas aeruginosa PAO1 (P. aeruginosa PAO1), and Salmonella typhimurium (S. typhimurium) at a concentration of approximately 1 × 105 CFU/mL after 48 h. Moreover, the antibacterial mechanism of Au@CD-MOF was investigated using E. coli O157:H7 and S. aureus as model organisms. The findings revealed that Au@CD-MOF disrupted the integrity of cell membranes and diminished their potential, consequently impeding the normal functions of the bacteria. Additionally, the heightened permeability of cell membranes induced by Au@CD-MOF resulted in substantial leakage of nucleic acids and proteins, ultimately leading to bacterial eradication.

Theoretical prediction of the unusual optical properties shown by the gold (Au) nanomaterials remains challenging. Based on this fact, some colloidal Au nanoparticles (AuNPs) were prepared in ethanol and demonized water using the versatile pulse laser ablation in liquid (PLAL) method and characterized. The pulsed laser irradiation energy-dependent optical absorbance and morphology of these AuNPs were determined. Analytical Mie–Gans scattering model was applied to interpret the experimentally observed absorption spectra of these colloidal AuNPs. In addition, the AuNPs size and shape-dependent absorbance were predicted accurately by fitting the recorded spectra with the analytical model simulation. The results revealed that the dielectric function of the AuNPs played a considerable role to realize the best fit of the experimental absorption data. The average sizes of the AuNPs predicted by the proposed analytical model were tallied well with the experimentally measured ones. It is found that an accuracy of more than 8% on the particle size between experimental and predicted data. It is established that the modified Mie–Gans scattering model can provide a better understanding of the distinct absorption attributes of the colloidal AuNPs synthesized by the PLAL method in various liquid media.Highlights Some AuNPs were prepared in ethanol and deionized water using the PLAL method.The morphology and absorbance of the produced AuNPs were determined.Absorption and scattering traits of these NPs were explained via the modified Mie–Gans model.Proposed AuNPs with distinct optical traits may be beneficial for practical applications.

Kristina Jakic,1 Michal Selc,1,2 Filip Razga,3 Veronika Nemethova,3 Petra Mazancova,3 Filip Havel,4,5 Michal Sramek,5 Monika Zarska,5 Jan Proska,4 Vlasta Masanova,6 Iveta Uhnakova,6 Peter Makovicky,7 Marta Novotova,8 Vit Vykoukal,9 Andrea Babelova1,2 1Department of Nanobiology, Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia; 2Centre for Advanced Material Application, Slovak Academy of Sciences, Bratislava, Slovakia; 3Selecta Biotech SE, Bratislava, Slovakia; 4Department of Physical Electronics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic; 5Department of Genome Integrity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic; 6Department of Metallomics, Faculty of Medicine, Slovak Medical University, Bratislava, Slovakia; 7Department of Molecular Oncology, Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia; 8Department of Cellular Cardiology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia; 9Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech RepublicCorrespondence: Andrea Babelova, Department of Nanobiology, Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia, Tel +421-2-32295-189, Fax +421-2-5477-4284, Email andrea.babelova@savba.skIntroduction: Gold nanoparticles are promising candidates as vehicles for drug delivery systems and could be developed into effective anticancer treatments. However, concerns about their safety need to be identified, addressed, and satisfactorily answered. Although gold nanoparticles are considered biocompatible and nontoxic, most of the toxicology evidence originates from in vitro studies, which may not reflect the responses in complex living organisms.Methods: We used an animal model to study the long-term effects of 20 nm spherical AuNPs coated with bovine serum albumin. Mice received a 1 mg/kg single intravenous dose of nanoparticles, and the biodistribution and accumulation, as well as the organ changes caused by the nanoparticles, were characterized in the liver, spleen, and kidneys during 120 days.Results: The amount of nanoparticles in the organs remained high at 120 days compared with day 1, showing a 39% reduction in the liver, a 53% increase in the spleen, and a 150% increase in the kidneys. The biological effects of chronic nanoparticle exposure were associated with early inflammatory and fibrotic responses in the organs and were more pronounced in the kidneys, despite a negligible amount of nanoparticles found in renal tissues.Conclusion: Our data suggest, that although AuNPs belong to the safest nanomaterial platforms nowadays, due to their slow tissue elimination leading to long-term accumulation in the biological systems, they may induce toxic responses in the vital organs, and so understanding of their long-term biological impact is important to consider their potential therapeutic applications. Keywords: AuNPs, in vivo, long-term accumulation, biodistribution, inflammation, fibrosis

Recently, metal nanoparticles synthesized by bio-fabrication methods were being used for various life-saving treatments. In our present study, AuNPs were fabricated using aqueous Panicum Maximum (P. Maximum) leaf extract. The analysis of UV–Visible spectrophotometer indicated the excitation of the formed AuNPs, specifically, a distinct SPR band positioned nearly at 530 nm. The formation of AuNPs with 45–50-nm size range was confirmed by TEM. Also, SAED pattern was utilized to characterize single crystalline nature of the biofabricated AuNPs. Further, the anticancer effects of synthesized AuNPs were studied against HepG2 cells. After incubating HepG2 cells with AuNPs, the amount of cytochrome c, CASP 9/CASP 8/CASP 3/BAX expression level, formation of ROS, and cell viability were analyzed. Outcomes of our study showed a dose determined cytotoxicity and half inhibitory concentration (IC50) of 75 μg/mL for the synthesized AuNPs. Cytotoxicity of AuNPs was accompanied by cell apoptosis and ROS induction in cell line of HepG2. Based on our results, AuNPs could have potential for development of new drugs for therapy of liver hepatocellular carcinoma in nursing care. [ABSTRACT FROM AUTHOR]

The rapid and precise monitoring of peripheral blood miRNA levels holds paramount importance for disease diagnosis and treatment monitoring. In this study, we propose an innovative research strategy that combines the catalytic hairpin assembly reaction with SERS signal congregation and enhancement. This combination can significantly enhance the stability of SERS detection, enabling stable and efficient detection of miRNA. Specifically, our paper-based SERS detection platform incorporates a streptavidin-modified substrate, biotin-labeled catalytic hairpin assembly reaction probes, 4-ATP, and primer-co-modified gold nanoparticles. In the presence of miRNA, the 4-ATP and primer-co-modified gold nanoparticles can specifically recognize the miRNA and interact with the biotin-labeled CHA probes to initiate an interfacial catalytic hairpin assembly reaction. This enzyme-free high-efficiency catalytic process can accumulate a large amount of biotin on the gold nanoparticles, which then bind to the streptavidin on the substrate with the assistance of the driving liquid, forming red gold nanoparticle stripes. These provide a multitude of hotspots for SERS, enabling enhanced signal detection. This innovative design achieves a low detection limit of 3.47 fM while maintaining excellent stability and repeatability. This conceptually innovative detection platform offers new technological possibilities and solutions for clinical miRNA detection. [ABSTRACT FROM AUTHOR]

In this work, nano-levodopa-liposomes (L-dopa-Lip) suspension was prepared by rotary-evaporated film-ultrasonic method, and freeze-drying powders of L-dopa-Lip were also obtained to improve the stability. The products were characterized by TEM, DLS, and TG-DSC, and the phase-transition temperature (Tm) and encapsulation efficiency were calculated. The brain-targeting and in vitro release of the drug was also studied. The results showed that L-dopa-Lip were well-formed spherical vesicles, and the sizes were about 100 nm, and the encapsulation efficiency was higher than 90%. The drug release temperature of L-dopa-Lip was 68 °C, and the in vitro release property and mathematical model were also studied. The brain targeting of L-dopa-Lip in vivo was explored by injecting the gold nanoparticles (AuNPs) labeled L-dopa-Lip (AuNPs-L-dopa-Lip) through the tail vein. ICP-MS and TEM showed that L-dopa-Lip had brain targeting, suggesting the potential treatment of L-dopa-Lip on brain dysfunction. The results of this work might be helpful for designing drug-loaded liposomes for the treatment of central nervous system (CNS) diseases and monitoring their distributions in vivo. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to develop and evaluate a lateral flow card for the detection of active Schistosoma haematobium infection. Methods: In order to prepare the immunochromatography lateral flow strip (ICLFS), antibodies purified from schistosomiasis were conjugated passively with gold nanoparticles using a potassium carbonate buffer. Results: The novel ICLFS was able to correctly identify 64 out of 67 samples of schistosomiasis, 6 out of 90 samples of other parasites, and 0 out of 27 control samples. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 95.5%, 93.3%, 90%, and 91.4% respectively. Comparatively, the sensitivity, specificity, NPV, and PPV of sandwich enzyme-linked immunosorbent assays (ELISA) conjugated with gold nanoparticles (AuNPs) were 91.1%, 88.8%, 85.9%, and 84.4% respectively. The increased sensitivity and specificity of ICLFS produced superior results to those of sandwich ELISA. Conclusion: In conclusion, ICLFS is more beneficial and precise than sandwich ELISA for detection of S. haematobium infection at early stage. [ABSTRACT FROM AUTHOR]

This work demonstrates the use of jute stick extract as a reducing and stabilizing agent for the synthesis of spherical gold nanoparticles (AuNPs). In UV‐Vis spectroscopy, peak at 550 nm was used to confirm the formation of AuNPs. The spherical surface morphology of AuNPs was determined through SEM and TEM analysis. While XRD investigation revealed the crystallinity of the prepared AuNPs. To ensure the biocompatibility of synthesized AuNPs, a bacterial investigation was conducted with negative results towards bacterial strain. The, modified FTO with AuNPs were able to detect glucose in CV analysis and the constructed sensor displayed a wide linear range of 50 μM to 40 mM with a detection limit of 20 μM. Scan rate analysis was performed to determine the charge transfer coefficient (0.42) and Tafel slope (102 mV/decade). Furthermore, the interfacial surface mechanism is illustrated to understand the interaction of glucose with the electrode surface in an alkaline medium and the product formation through the dehydrogenation and hydrolysis process. The prepared sensor also showed good stability, reproducibility, and anti‐interference capabilities. In the case of real sample analysis, we used a blood serum sample. A low RSD value (<10 %) suggests the practical use of AuNPs/FTO in real‐life applications. [ABSTRACT FROM AUTHOR]

The development of nanozymes, artificial enzymes made from inorganic nanoparticles, is widely studied due to their affordability, durability, and strength. Gold nanoparticles (AuNPs) are employed to imitate peroxidase, glucose oxidase, lactate oxidase, superoxide dismutase, and catalase. The last one transforms intracellular hydrogen peroxide into molecular oxygen, whose deficiency is characteristic of the hypoxic tumor microenvironment. Thus, gold nanoparticles are thought to enhance the overall effectiveness of photodynamic therapy. However, the enzyme‐like activity of nanoparticles rapidly decreases in biological media, due to the aggregation and formation of the so‐called "protein corona". In this study, polymeric submicrocapsules loaded with AuNPs and a photodynamic dye are fabricated via Layer‐by‐Layer (LbL) assembly. The enhancement of photodynamic treatment efficacy by in situ production of oxygen by the catalase‐like effect of AuNPs is investigated. Polymeric capsules are thoroughly characterized in terms of physicochemical and catalytic properties, and as a proof of concept, their therapeutic potential is evaluated in vitro. Furthermore, encapsulated AuNPs shows significantly lower aggregation both upon storage and during the reaction course. The results shows that the polymer capsules, containing AuNPs and photodynamic dye, show significantly higher light‐induced cytotoxicity in comparison to the individual photodynamic dye, suggesting a synergistic effect between the formation of molecular oxygen by catalase‐like gold nanozymes and photodynamic action. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) self-assembled AuNPs/Ti3C2 MXene hydrogel (AuNPs/Ti3C2 MXH) nanocomposite was prepared for the fabrication of a novel microRNA-122 electrochemical biosensor. The 3D hydrogel structure was gelated from two-dimensional MXene nanosheets with the assistance of graphite oxide and ethylenediamine. MXene hydrogels supported the in situ formation of Au nanoparticles (AuNPs) that predominantly exploring the (111) facet, and these AuNPs are utilized as carriers for hairpin DNA (hpDNA) probes, facilitating DNA hybridization. MXene acted as both a reductant and stabilizer, significantly improving the electrochemical signal. In addition, the conjugation of PAMAM dendrimer-encapsulated AuNPs and H-DNA worked as an ideal bridge to connect targets and efficient electrochemical tags, providing a high amplification efficiency for the sensing of microRNA-122. A linear relationship between the peak currents and the logarithm of the concentrations of microRNA-122 from 1.0 × 10−2 to 1.0 × 102 fM (I = 1.642 + 0.312 lgc, R2 = 0.9891), is obtained. The detection limit is 0.8 × 10−2 fM (S/N = 3). The average recovery for human serum detection ranged from 97.32 to 101.4% (RSD < 5%). [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic over recent years has shown a great need for the rapid, low-cost, and on-site detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, an aptamer-based colloidal gold nanoparticle lateral flow test strip was well developed to realize the visual detection of wild-type SARS-CoV-2 spike proteins (SPs) and multiple variants. Under the optimal reaction conditions, a low detection limit of SARS-CoV-2 S proteins of 0.68 nM was acquired, and the actual detection recovery was 83.3% to 108.8% for real-world samples. This suggests a potential tool for the prompt detection of SARS-CoV-2 with good sensitivity and accuracy, and a new method for the development of alternative antibody test strips for the detection of other viral targets. [ABSTRACT FROM AUTHOR]

Early detection of diseases can increase the chances of successful treatment and survival. Therefore, it is necessary to develop a method for detecting or sensing biomolecules that cause trouble in living organisms. Disease sensors should possess specific properties, such as selectivity, reproducibility, stability, sensitivity, and morphology, for their routine application in medical diagnosis and treatment. This work focuses on biosensors in the form of surface-functionalized gold (AuNPs) and silver nanoparticles (AgNPs) prepared using a less-time-consuming, inexpensive, and efficient synthesis route. This allows for the production of highly pure and stable (non-aggregating without stabilizers) nanoparticles with a well-defined spherical shape, a desired diameter, and a monodisperse distribution in an aqueous environment, as confirmed by transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDS), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), ultraviolet-visible (UV-VIS) spectroscopy, and dynamic light scattering (DLS). Thus, these nanoparticles can be used routinely as biomarker sensors and drug-delivery platforms for precision medicine treatment. The NPs' surface was coated with phosphonate dipeptides of L-leucine (Leu; l-Leu–C(R1)(R2)PO3H2), and their adsorption was monitored using SERS. Reproducible spectra were analyzed to determine the orientation of the dipeptides (coating layers) on the nanoparticles' surface. The appropriate R2 side chain of the dipeptide can be selected to control the arrangement of these dipeptides. This allows for the proper formation of a layer covering the nanoparticles while also simultaneously interacting with the surrounding biological environment, such as cells, tissues, and biological fluids. [ABSTRACT FROM AUTHOR]

In the present work, an easy one-pot environmentally friendly method is demonstrated where the extract of Memecylon edule was utilized for the synthesis of gold nanoparticles (Au NPs) through the reduction of chloroauric acid (HAuCl4). The synthesized NPs were studied using various spectroscopic and microscopic techniques. UV-visible (UV-Vis) results indicated the formation of AuNPs with optical absorption peak found at 537 nm. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis confirmed the formation of AuNPs with size ranges from 25 to 30 nm. FTIR results confirmed the capping of AuNPs with Memecylon edule extract polyphenols. Energy-dispersive spectroscopy (EDS) results confirmed the AuNPs with existence of elemental peaks corresponding to gold. Additionally, the present study also described the combined effect of bio-fabricated AuNPs with ultrasound treatment for higher destruction of cancerous cells. Flow cytometry results showed the effect of AuNPs and ultrasound on pediatric acute myeloid leukemia cell lines (Kasumi-1) and normal CMK cell lines, which exhibited a negligible reduction in the percentage of viable cells with combined treatment towards the normal CMK cells. Moreover, the percent of viable Kasumi-1 cells displayed a noteworthy decline for the combined treatment of AuNPs with US. Furthermore, these outcomes indicated that AuNP-aided US therapy can act as an active and unique approach for the target of cancer cells destruction. [ABSTRACT FROM AUTHOR]

The layer-by-layer (LbL) method demonstrates significant versatility for constructing substrates with nanoscale-thick layers and diverse compositions. This technique is based on alternate deposition of species that interact electrostatically. Studies have demonstrated that this technique holds promise for use as a surface-enhanced Raman scattering (SERS) substrate, enabling the detection of pesticides at low concentrations and finding applications in the biological field. In this study, a simple methodology based on the layer-by-layer (LbL) method was developed to construct SERS substrates. Substrates with varying numbers of bilayers (1, 5, or 10) were built on glass slides. The positive layer was composed of the natural polysaccharide chitosan. In contrast, the negative layer consists of gold nanoparticles (AuNPs) with a negative charge on their surface, achieved using sodium citrate as a reducing agent. The SERS substrates were characterized by UV–VIS-NIR spectroscopy and atomic force microscopy (AFM). They were tested as SERS substrates by utilizing thiophenol (TP) at a concentration of 1.0 × 10–3 mol L−1. The distribution of the SERS signal was monitored through the 417 cm−1 peak, which is attributed to the CH stretching mode characteristic of TP. The substrates exhibited a more significant enhancement with an increase in the number of bilayers. They have proven highly promising for future applications, such as diagnostic evaluation of diseases, detection of pesticide molecules, biological molecules, and various other applications. [ABSTRACT FROM AUTHOR]

Sang Mi Park,1,2 Da Yeon Kim,3 Kyeong Hyeon Lee,1 Yong-Il Shin,1,4 Sang-Cheol Han,5 Sang-Mo Kwon1,2 1Department of Physiology, Laboratory of Vascular Medicine and Stem Cell Biology, School of Medicine, Pusan National University, Yangsan, Republic of Korea; 2BK21 GRAND Convergence Medical Science Education Research Center, Pusan National University, Yangsan, South Korea; 3Genetic & Epigenetic Toxicology Research Group, Korea Institute of Toxicology (KIT), Daejeon, Republic of Korea; 4Department of Rehabilitation Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea; 5CEN Co., Ltd. Nanoconvergence Center, Muan-ro, Miryang, 761, Republic of KoreaCorrespondence: Sang-Mo Kwon, Department of Physiology, Laboratory of Vascular Medicine and Stem Cell Biology, School of Medicine, Pusan National University, Yangsan, Republic of Korea, Tel +82-51-510-8072, Fax +82-51-510-8076, Email smkwon323@pusan.ac.krPurpose: 5-fluorouracil (5-FU) is a first-line chemotherapeutic agent used to treat colorectal cancer (CRC). However, 5-FU induces drug resistance and activation of cancer stem cells (CSCs). In the present study, we designed a novel biocompatible nanomedicine system with high efficacy and biocompatibility by synthesizing mesoporous silica nanoparticle (MSN)-structured ZnO and gold ions. Oleuropein (OLP) is a phenolic compound derived from olive leaves that exerts anti-cancer effects. Therefore, we synthesized OLP-loaded ZnO/Au MSNs (ZnO/Au/OLP MSNs) and examined their anti-cancer effects on 5-FU-resistant CRC cells.Methods: ZnO/Au MSNs were synthesized and functionalized, and their physical and chemical compositions were characterized using UV-visible spectroscopy, dynamic light scattering, and transmission electron microscopy (TEM). Their effects were assessed in terms of cellular proliferation capacity, migration and invasion ability, colony-forming ability, spheroid-forming ability, reactive oxygen species (ROS) production, and mitochondrial membrane depolarization.Results: ZnO/Au MSNs were mostly composed of various ions containing ZnO and gold ions, had a spheroid phenotype, and exhibited no cytotoxicity. ZnO/Au/OLP MSNs reduced cell viability and CSC formation and induced apoptosis of 5-FU-resistant CRC cells via necrosis via ROS accumulation and DNA fragmentation.Conclusion: ZnO/Au/OLP MSNs exhibited anti-cancer activity by upregulating necrosis. These results revealed that ZnO/Au/OLP MSNs are a novel drug delivery system for 5-FU CRC therapy.Keywords: gold nanoparticles, drug resistance, MSNs, AuNPs, colorectal cancer cell, oleuropein

ObjectiveBrassinolide is an important endogenous plant hormone. In this work, an electrochemical immunosensor for in situ detection of brassinolide was constructed using screen-printed electrode (SPE).MethodsAu nanoparticles (AuNPs) were firstly electrodeposited on the surface of SPE electrode by electrochemical workstation, and then CuCl2 nanowires (CuCl2 NWs) were added to the electrode, which can not only increase the conductivity of the electrode, but also Cu2+ can be used as a REDOX probe for the sensor. Finally, Mxene and polydopamine nanocomposite (Mxene@PDA) were selected as the modification materials for SPE electrodes because Mxene has the advantages of large surface area and good electrical conductivity, which can further amplify Cu2+ signals. However, Mxene is easily oxidized and unstable in air. Polydopamine (PDA) contains a large number of catechol and amino groups, which are coated on the surface of Mxene after self-polymerization by dopamine, cutting off the path of oxygen penetration, making Mxene difficult to be oxidized. Mxene@PDA can also be used as a coupling agent to fix more antibodies on the electrode surface, improving the overall biocompatibility, and improve the overall biocompatibility.Results and DiscussionsThe sensor has a wide linear detection range: 0.1 pg/mL to 1 mg/mL, and the detection limit was 0.015 pg/ml (S/N=3). In addition, the content of endogenous brassinolide in wheat was detected by SPE electrodes in vitro and the recovery rate was 98.13% to 104.74%.While verifying the accuracy of the sensor, it also demonstrated its superior stability and sensitivity. Besides, the sensor also showed excellent application potential in the in situ detection of brassinosteroids from wheat leaves. Compared with other brassinolide detection methods, the immunosensor developed in this study has better analytical performance.ConclusionsAn electrochemical immunosensor for in situ detection of brassinolide was developed for the first time, providing a good electrochemical platform for in situ determination of brassinolide in plant leaves, which has great application potential in precision agriculture.

Detecting exosomal markers using laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF MS) is a novel approach for examining liquid biopsies of non‐small cell lung cancer (NSCLC) samples. However, LDI‐TOF MS is limited by low sensitivity and poor reproducibility when analyzing intact proteins directly. In this report, gold nanoparticles/cellulose nanocrystals (AuNPs/CNC) is introduced as the matrix for direct analysis of intact proteins in NSCLC serum exosomes. AuNPs/CNC with "dual dispersion" effects dispersed and stabilized AuNPs and improved ion inhibition effects caused by protein aggregation. These features increased the signal‐to‐noise ratio of [M+H]+ peaks by two orders of magnitude and lowered the detection limit of intact proteins to 0.01 mg mL–1. The coefficient of variation with or without AuNPs/CNC is measured as 10.2% and 32.5%, respectively. The excellent reproducibility yielded a linear relationship (y = 15.41x – 7.983, R2 = 0.989) over the protein concentration range of 0.01 to 20 mg mL–1. Finally, AuNPs/CNC‐assisted LDI‐TOF MS provides clinically relevant fingerprint information of exosomal proteins in NSCLC serum, and characteristic proteins S100 calcium‐binding protein A10, Urokinase plasminogen activator surface receptor, Plasma protease C1 inhibitor, Tyrosine‐protein kinase Fgr and Mannose‐binding lectin associated serine protease 2 represented excellent predictive biomarkers of NSCLC risk. [ABSTRACT FROM AUTHOR]

In this study, the gold nanoparticles (AuNPs) supported by a covalent organic framework (COF) were designed and produced by a self-reduction method, which could effectively avoid the aggregation of AuNPs. The amino and aldehyde groups in the COF are crucial for the self-reduction of AuNPs. The porous COF with a high specific surface area not only serves as an anchoring platform for AuNPs but also enhances the adsorption abilities toward acetaminophen (AP). The AuNPs can facilitate the electron transfer capabilities of the catalyst and enhance the electrocatalytic activity of the catalyst. Due to the excellent electrical conductivity of carbon nanotubes, COF@AuNPs were composited with multi-walled carbon nanotubes (MWCNTs) by the ultrasound method. COF@AuNPs@MWCNTs were applied to build an electrochemical sensing platform to measure AP. The COF@AuNPs@MWCNTs/GCE displays a wide detection range for AP (0.1–500, 500–1200 μM) with a detection limit of 80 nM. The constructed electrochemical sensor can be utilized for the assay of AP in the actual sample serum with recoveries of 98.20–102.2%. Such a self-reducing synthesis method opens up perspectives for the design of COF@metal NPs for a broad range of applications such as sensing, energy, and catalysis. [ABSTRACT FROM AUTHOR]

The influenza virus is a pervasive pathogen that exhibits increased prevalence during colder seasons, resulting in a significant annual occurrence of infections. Notably, pharmaceutical interventions effective against influenza A strains often exhibit limited efficacy against influenza B variants. Against this backdrop, the need for innovative approaches to accurately and swiftly differentiate and detect influenza B becomes evident. Biosensors play a pivotal role in this detection process, offering rapid, specific, and sensitive identification of the virus, facilitating timely intervention and containment efforts. Oligonucleotide sequences targeting the conserved B/Victoria/2/87 influenza virus NP region were designed. Nasopharyngeal swabs were collected from patients suspected of influenza virus infection, and viral RNA was extracted. RNA quality was assessed through one‐step PCR. cDNA synthesis was performed using random hexamers, and real‐time PCR quantified the influenza genome. Gold nanoparticles were immobilized on a surface to immobilize the specific DNA probe, and electrochemical hybridization was electrochemically followed. The biosensor exhibited high selectivity and effective distinction of complementary sequences from mismatches and influenza virus cDNA genome. The biosensor successfully detected the influenza B virus genome in real samples. Non‐influenza samples yielded no significant hybridization signals. The comparison between the results obtained from the biosensor and real‐time PCR revealed full agreement of these methods. The biosensor utilized electrochemical detection of hybridization and proved effective in detecting the influenza B virus genome with high specificity, sensitivity, and selectivity. Comparative analysis with real‐time PCR underscored the accuracy and potential applicability of the biosensor in rapid and specific virus detection. This innovative approach holds promise for future diagnostic and epidemiological applications in detecting influenza B virus and other pathogens. [ABSTRACT FROM AUTHOR]

A green chemistry approach to the synthesis of AuNPs using the pelletized culture of Termitomyces heimii has been attempted. The treatment of pellets of Termitomyces heimii and chloroauric acid resulted in the formation of AuNPs. These were characterized using various techniques like UV–visible spectroscopy, X-ray diffraction studies (XRD), Energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), zeta potential, dynamic light scattering (DLS), Fourier Transform Infrared Spectrometry (FTIR), and Raman spectroscopy. The results showed the color change of the interaction mixture from light yellow to purple after 25 min. AuNPs showed max absorbance at 530 nm using a UV–visible spectrum, as evident in forming AuNPs. FTIR spectra revealed the presence of functional groups related to peptides, proteins, monosaccharides, and phenolic compounds, which reduced Gold ions. The EDX technique confirmed the formation of AuNPs. XRD results showed that AuNPs have a face-centered cubic (fcc) crystal. The TEM images showed a successful synthesis of triangular nano prisms to nearly spherical and hexagonal with different sizes ranging between 20 and 150 nm. [ABSTRACT FROM AUTHOR]

Metal nanoparticles (MNPs) have gained significant attention in recent years for their potential use as effective antimicrobial agents for controlling plant pathogens. This review article summarizes the recent advances in the role of MNPs in the control of plant pathogens, focusing on their mechanisms of action, applications, and limitations. MNPs can act as a broad-spectrum antimicrobial agent against various plant pathogens, including bacteria, fungi, and viruses. Different types of MNPs, such as silver, copper, zinc, iron, and gold, have been studied for their antimicrobial properties. The unique physicochemical properties of MNPs, such as their small size, large surface area, and high reactivity, allow them to interact with plant pathogens at the molecular level, leading to disruption of the cell membrane, inhibition of cellular respiration, and generation of reactive oxygen species. The use of MNPs in plant pathogen control has several advantages, including their low toxicity, selectivity, and biodegradability. However, their effectiveness can be influenced by several factors, including the type of MNP, concentration, and mode of application. This review highlights the current state of knowledge on the use of MNPs in plant pathogen control and discusses the future prospects and challenges in the field. Overall, the review provides insight into the potential of MNPs as a promising alternative to conventional chemical agents for controlling plant pathogens. [ABSTRACT FROM AUTHOR]