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In this work, we explored the impact of zwitterionic surfactants, sulfobetaine 16 (SB-16) and a PEG-phospholipid conjugate (DSPE-PEG), on nanosensor performance. We fabricated four sensors (for Na+, K+, Al3+, and O2) and examined how these surfactants influenced various aspects, including fabrication methods, sensing mechanisms, and the incorporation of nanomaterials. Our results highlighted SB-16's role in enhancing selectivity in ion-exchange sensors (Na+ and K+) while maintaining sensitivity akin to its PEG counterpart. The liquid–liquid extraction based sensors (Al3+) were unaffected by surfactant choice, while the O2 sensors that operate via collisional quenching exhibited reduced sensitivity with SB-16 when compared to its PEG-based counterpart. Additionally, the SB-16 sensors proved adaptable to different fabrication approaches (SESE – single emulsion solvent evaporation and FNP – flash nanoprecipitation), showcased good cell viability and maintained a functional lifetime of at least five days. Furthermore, via the use of quantum dots, we showed that it is possible to incorporate other nanomaterials into the sensing phase of SB-16 sensors. Future investigations could target enhancing the pH stability of zwitterionic surfactants to further advance their applicability in sensor technologies. [ABSTRACT FROM AUTHOR]

Mitochondria, one of the most important organelles, represent a crucial subcellular target for fundamental research and biomedical applications. Despite significant advances in the design of DNA nanotechnologies for a variety of bio‐applications, the dearth of strategies that enable mitochondria targeting for subcellular molecular imaging and therapy remains an outstanding challenge in this field. In this Minireview, we summarize the recent progresses on the emerging design and application of DNA nanotechnology for mitochondria‐targeted molecular imaging and tumor treatment. We first highlight the engineering of mitochondria‐localized DNA nanosensors for in situ detection and imaging of diverse key molecules that are essential to maintain mitochondrial functions, including mitochondrial DNA and microRNA, enzymes, small molecules, and metal ions. Then, we compile the developments of DNA nanotechnologies for mitochondria‐targeted anti‐tumor therapy, including modularly designed DNA nanodevices for subcellular delivery of therapeutic agents, and programmed DNA assembly for mitochondrial interference. We will place an emphasis on clarification of the chemical principles of how DNA nanobiotechnology can be designed to target mitochondria for various biomedical applications. Finally, the remaining challenges and future directions in this emerging field will be discussed, hoping to inspire further development of advanced DNA toolkits for both academic and clinical research regarding mitochondria. [ABSTRACT FROM AUTHOR]

Chemical sensors, relying on changes in the electrical conductance of a gas-sensitive material due to the surrounding gas, typically react with multiple target gases and the resulting response is not specific for a certain analyte species. The purpose of this study was the development of a multi-sensor platform for systematic screening of gas-sensitive nanomaterials. We have developed a specific Si-based platform chip, which integrates a total of 16 sensor structures. Along with a newly developed measurement setup, this multi-sensor platform enables simultaneous performance characterization of up to 16 different sensor materials in parallel in an automated gas measurement setup. In this study, we chose the well-established ultrathin SnO2 films as base material. In order to screen the sensor performance towards type and areal density of nanoparticles on the SnO2 films, the films are functionalized by ESJET printing Au-, NiPt-, and Pd-nanoparticle solutions with five different concentrations. The functionalized sensors have been tested toward the target gases: carbon monoxide and a specific hydrogen carbon gas mixture of acetylene, ethane, ethne, and propene. The measurements have been performed in three different humidity conditions (25%, 50% and 75% r.h.). We have found that all investigated types of NPs (except Pd) increase the responses of the sensors towards CO and HCmix and reach a maximum for an NP type specific concentration. [ABSTRACT FROM AUTHOR]

Monitoring personal ultraviolet (UV) exposure facilitates risk mitigation against UV‐induced skin aging and skin cancer, the most common malignancy in North America, Europe, and Australia. UV radiometers convey real‐time information on local UV irradiance, while UV dosimeters count accumulated UV exposure over time. These devices can help users manage exposure levels in order to reach a healthy daily dose of UV light required for vitamin D production without exceeding erythemal limits that would increase skin cancer risk. However, personal UV detectors still suffer from several limitations. Wearable electronic UV sensors are relatively bulky, heavy, and expensive, while the more commonly used on‐skin disposable colorimetric UV sensors suffer from short service life, skin discomfort, and high accumulated costs when used daily as recommended. Intradermal colorimetric UV nanosensors can overcome these limitations, offering long‐term, comfortable, and inexpensive naked‐eye colorimetric indication of intradermal UV irradiance. Now, a new generation of UV‐sensing intradermal pigments with an improved design offers better tunability, stability, and biocompatibility. These UV‐photochromic nanosensors may be operated as UV dosimeters or simple sunscreen efficacy monitors, depending on the formulation, and can remain functional and re‐usable in the dermis for years. [ABSTRACT FROM AUTHOR]

Luminescent carbon nanoparticles, such as carbon quantum dots (CQDs) and graphene quantum dots (GQDs), are increasingly utilized for sarcosine detection due to their exceptional water permeability, sustained luminescence, and biocompatibility. Sarcosine as a biomarker holds significance for therapeutic purposes and disease identification. Carbon‐based sensors offer eco‐friendliness, recyclability, and affordability, making them sustainable for sensing applications across various domains. Despite the widespread use of standard sensors for sarcosine measurement, they face limitations. This paper presents a focused review of recent developments in biosensors utilizing luminescent carbon quantum dots and graphene quantum dots for sarcosine detection. Key processes are characterized by their selectivity and sensitivity to different forms of sarcosine and interfering substances like metallic ions and amino acids. The significant reaction mechanisms and detection methods for sarcosine are outlined and compared. Additionally, the challenges in developing functionalized CQDs and GQDs for further investigation are explored. In summary, luminescent carbon nanoparticles offer a promising avenue for sarcosine detection, addressing limitations of standard sensors through their cost‐effectiveness, sensitivity, and rapid response, thus holding potential for diverse sensing applications. [ABSTRACT FROM AUTHOR]

The unique mechanical properties of graphene have made it a topic of enormous research interest over the last few years. Studying graphene's pull-in instability is key for its application in nanoelectromechanical systems. Understanding the thresholds of this instability helps prevent failure in graphene-based nanoelectromechanical systems, such as sensors and actuators, maintaining device performance and lifespan. In this paper, based on stress-driven nonlocal elasticity, a new size-dependent multi-beam shear model was presented to investigate the pull-in instability of multilayer graphene/substrate nano-sensors. The sensor bends towards the graphene layer because of the thermomechanical mismatch during the fabrication process. Therefore, the curvature effect is included in the proposed model. Also, the impact of the Casimir force is considered in the modeling. A finite element method has been used to simulate the nano-sensor and to obtain the pull-in instability. For validation, the pull-in voltage values obtained from the presented methodology have been compared with the results of others. Finally, considering different numbers of graphene layers and geometrical parameters such as length, initial gap, and curvature, it can be seen how these parameters affect the instability voltage of this nano-sensor. [ABSTRACT FROM AUTHOR]

This paper presents a new biosensor design based on the Kretschmann configuration, for the detection of analytes at different refractive indices. Our studied design consists of a TiO2/SiO2 bi-layer sandwiched between a BK7 prism and a bimetallic layer of Ag/Au plasmonic materials, covered by a layer of black phosphorus placed below the analyte-containing detection medium. The different layers of our structure and analyte detection were optimized using the angular interrogation method. High performance was achieved, with a sensitivity of 240 deg/RIU and a quality factor of 34.7 RIU−1. This biosensor can detect analytes with a wide refractive index range between 1.330 and 1.347, such as glucose detection in urine samples using a refractive index variation of 10 − 3 . This capability offers a wide range of applications for biomedical and biochemical detection and selectivity. [ABSTRACT FROM AUTHOR]

Green silver nanoparticle-based spectrophotometric and spectrofluorimetric measurements for tioguanine (TG) determination are reported in this study as a reliable, non-toxic approach with a sensitive and effective green assembly. TG is an anti-cancer medication used to treat leukemia. Chemical-based method development for its analysis purpose may have a dangerous effect on the environment. Cleaner, more affordable methods have received a lot of attention lately. By using Box–Behnken design under a response surface approach, the factors essential for the synthesis of green silver nanoparticles were optimized. For the two approaches, experimental optimization resulted in linear dynamic ranges of 55–220 and 65–200 nM, respectively. The technique was sensitive enough to detect and quantify TG at concentrations of 6.6 and 12.4 nM, respectively. The devised method is validated by satisfactory findings for the statistical treatment of the analytical data in accordance with the ICH requirements. Green nanoparticle formation was supported by X-ray diffraction analysis, scanning electron microscopy, and infrared spectroscopy analysis. When the developed nanosensors were used with the formulations, the relative standard deviation achieved was less than 2%. The photocatalytic degradation of acid fuchsin dye produced results that demonstrated the possible application of the developed nanosensors. [ABSTRACT FROM AUTHOR]

Mycotoxins are toxic secondary metabolites produced by certain molds and fungi that contaminate various food commodities, posing serious adverse effects on humans and animals. Aflatoxin, ochratoxin, trichothecene, fumonisin, zearalenone, patulin, and citrinin are some of the major mycotoxins affecting food and feed. The scientific community has focused on regulating food and feed materials due to their potential risks. Conventional techniques for mycotoxin detection have certain limitations in terms of sensitivity, specificity, and speed. In recent years, nanotechnology has emerged as a promising approach to revolutionize mycotoxin detection. This review provides an overview of nanotechnology‐based detection methods for mycotoxins in food and feed, discussing the basic aspects of mycotoxins, their health hazards, and conventional methods. It also explores various nanosensors and nanodevices developed to improve the sensitivity, selectivity, and speed of mycotoxin detection, thereby enhancing food safety and security. [ABSTRACT FROM AUTHOR]

A novel plasmonic structure is proposed to achieve plasmon-induced transparency (PIT), which is composed of a stub resonator (SR) and a square ring resonator (SRR). The research delves into the theoretical calculations and numerical simulations to explore the formation and evolution mechanisms of PIT. In this innovative structure, the evolution of PIT is notably influenced by geometric parameters, and its sensing performance in various environments is thoroughly examined. Furthermore, the study evaluates its potential applications in the domains of slow light and optical switches. Moreover, the introduction of an additional SR and SRR to the original structure leads to a multi-PIT phenomenon, and the underlying reasons for this phenomenon are elucidated. Meanwhile, the sensor sensitivity in air, alcohol, and glucose media is calculated to be improved by 12.5%, 12.7%, and 9.1%, respectively, compared with the previous work. This hybrid structure effectively enhances the overall performance of the plasmonic system in practical applications. Consequently, this proposed plasmonic structure introduces a fresh perspective for the development of multifunctional nanoscale optical devices, particularly in the realms of nanosensors, slow light technologies, optical storage, and optical switches. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) non‐layered materials, along with their unique surface properties, offer intriguing prospects for sensing applications. Introducing mechanical degrees of freedom is expected to enrich the sensing performances of 2D non‐layered devices, such as high frequency, high tunability, and large dynamic range, which could lead to new types of high performance nanosensors. Here, we demonstrate 2D non‐layered nanomechanical resonant sensors based on β‐In2S3, where the devices exhibit robust nanomechanical vibrations up to the very high frequency (VHF) band. We show that such device can operate as pressure sensor with broad range (from 10−3 Torr to atmospheric pressure), high linearity (with a nonlinearity factor as low as 0.0071), and fast response (with an intrinsic response time less than 1 μs). We further unveil the frequency scaling law in these β‐In2S3 nanomechanical sensors and successfully extract both the Young's modulus and pretension for the crystal. Our work paves the way towards future wafer‐scale design and integrated sensors based on 2D non‐layered materials. [ABSTRACT FROM AUTHOR]

A novel force sensor exploiting the interaction between plasmonic nanostructures and upconversion nanoparticles (UCNPs) is reported. The nanosensor is composed of a gold nanodisk and UCNPs separated by a flexible polymer layer. The gold nanodisk is designed to exhibit a plasmon resonance that selectively enhances one of the emission bands of the UCNPs while leaving the other ones largely unaffected. As the nanosensor is compressed or stretched by an external force, the polymer layer thickness changes, modulating the plasmon‐UCNP coupling. The resulting changes in the luminescence intensity provide the basis for sensing. Furthermore, the nanosensor employs ratiometric sensing, which makes it highly robust against any environmental variations. The nanosensors exhibit two orders of magnitude higher responsivity than previously reported UCNP‐based force sensors. They can be prepared as an on‐chip sensor array or in a colloidal solution, making them suitable for a variety of applications in biology and robotics. [ABSTRACT FROM AUTHOR]

Timely detection of early‐stage cancer holds immense potential in enhancing prognostic outcomes. There is an increasing desire for versatile tools to enable simple, sensitive, and cost‐effective cancer detection. By exploiting the extraintestinal metabolic inertness and efficiency renal clearance of sucrose, we designed a liposome nanosensor using sucrose as a messenger to convert tumor‐specific esterase activity into glucose meter readout, enabling economical and sensitive urinalysis for cancer detection in point‐of‐care testing (POCT). Our results demonstrate that the nanosensors exhibited significant signal differences between tumor‐bearing and healthy mice in both orthotopic and metastatic tumor models. Additionally, efficient elimination of the nanosensors through the hepatobiliary pathway was observed with no significant toxicity. Such a non‐invasive diagnostic modality significantly assists in personalized pharmacological treatment and follow‐up efficacy assessment. We envision that this modular liposome nanosensor platform might be applied for economically detecting diverse diseases via a simple urinary test. [ABSTRACT FROM AUTHOR]

ATP plays a crucial role in cell energy supply, so the quantification of intracellular ATP levels is particularly important for understanding many physio-pathological processes. The intracellular quantification of this non-electroactive molecule can be realized using aptamer-modified nanoelectrodes, but is hindered by the limited quantity of modification and electroactive tags on the nanosized electrodes. Herein, we developed a simple but effective electrochemical signal amplification strategy for intracellular ATP detection, which replaces the regular ATP aptamer-linked ferrocene monomer with a polymer, thus greatly magnifying the amounts of electrochemical reporters linked to one chain of the aptamer and enhancing the signals. This ferrocene polymer–ATP aptamer was further immobilized onto Au nanowire electrodes (SiC@C@Au NWEs) to achieve accurate quantification of intracellular ATP in single cells, presenting high electrochemical signal output and high specificity. This work not only provides a powerful tool for quantifying intracellular ATP but also offers a simple and versatile strategy for electrochemical signal amplification in the detection of broader non-electroactive molecules involved in different kinds of intracellular physiological processes. [ABSTRACT FROM AUTHOR]

Sensing devices for rapid analytics are important societal requirements, with wide applications in environmental diagnostics, food testing, and disease screening. Nanomaterials present excellent opportunities in sensing applications owing to their superior structural strength, and their electronic, magnetic, and optoelectronic properties. Among the various mechanisms of gas sensing, including chemiresistive sensors, electrochemical sensors, and acoustic sensors, another promising area in this field involves plasmonic sensors. The advantage of nanomaterial-plasmonic sensors lies in the vast opportunities for tuning the sensor performance by optimizing the nanomaterial structure, thereby producing highly selective and sensitive sensors. Recently, several novel plasmonic sensors have been reported, with various configurations such as nanoarray resonator-, ring resonator-, and fibre-based plasmonic sensors. Going beyond noble metals, some promising nanomaterials for developing plasmonic gas sensor devices include two-dimensional materials, viz. graphene, transition metal dichalcogenides, black phosphorus, blue phosphorus, and MXenes. Their properties can be tuned by creating hybrid structures with layers of nanomaterials and metals, and the introduction of dopants or defects. Such strategies can be employed to improve the device performance in terms of its dynamic range, selectivity, and stability of the response signal. In this review, we have presented the fundamental properties of plasmons that facilitate its application in sensor devices, the mechanism of sensing, and have reviewed recent literature on nanomaterial-based plasmonic gas sensors. This review briefly describes the status quo of the field and prospects. [ABSTRACT FROM AUTHOR]

Fluorescent nanosensors are one of the most efficient techniques used for detection of toxic metal ions, based on ligand embedded into mesoporous materials. In this study, four different novel nanosensors NS1, NS2, NS3, and NS4 have been synthesized by incorporating fluorescent probes containing dihydropyridine and dihydropyrimidinone fragments into amino‐functionalized controllable (Ba0.8Sr0.2)CO3@Mesoporous silicate core/shell nanocomposite. The designed nanosensors were characterized by FT‐IR (Fourier‐transform infrared spectroscopy), X‐ray diffraction, transmission electron microscopy (TEM), and nitrogen adsorption–desorption isotherms. Visual naked‐eye observations and emission technique were employed to investigate the recognition and sensing capability of the investigated nanosensors toward various metal ions (Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, and Cu2+). A great quenching in the fluorescence intensity was clearly observed with the majority of studied metal ions for all the nanosensors. The binding constants and limit of detection (LOD) have been calculated. Cu2+ is the strongest binded one with both NS1 and NS2, while Al3+ and Fe3+ are the strongest binded metal ions with NS3 and NS4, respectively. The obtained results confirmed the high ability of the nanosensors to detect heavy metals ions at environmentally relevant concentrations using simple and low‐cost experimental studies with good reversibility and reusability. [ABSTRACT FROM AUTHOR]

A composite is a material in which more than one metal salt or polymer can be mixed to enhance the processed product's physical and chemical properties. Due to their high band gap and enhanced excitation energy, composites can be used in numerous areas, such as solar cells, fuel cells, catalysts, and energy storage. Over a large area of applications in different fields, few studies have examined the ability of composites to sense the efficiency of riboflavin/vitamin B2. The present work explores the utilisation of trimetallic-based nanocomposite nanoparticles (TMNCsNPs) as a sensing material, which is synthesised and characterised in detail. The TMNCsNPs were used to understand the exposure of riboflavin to glassy carbon electrodes (GCE). Several electrochemical parameters were selected for the electrochemical study of the processed sensor. Initially, a long-range concentration of riboflavin (0.976–125 μM in PBS) was selected to check the efficiency of the produced sensor (TMNCsNPs/GCE). Low-to high-potential windows (0.5–15 mV/s) were chosen to measure the effect on TMNCsNPs/GCE in PBS. The chronoamperometry (CA) responses were analysed at different time intervals (0–900 s). The cyclic response (CR) was analysed for TMNCsNPs/GCE sensor for up to one month. The interference of metal was examined, and real sample analysis was also conducted and discussed with possible mechanism. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, the detection and determination of numerous drugs and pharmaceuticals in various media have become crucial aspects of modern healthcare and environmental management. Among the available sensing techniques, electrochemical methods, particularly those utilising screen-printed electrodes (SPEs) and different portable equipment have emerged as rapid, effective, sensitive, and inexpensive. This study focuses on the detection of the anti-inflammatory drug diclofenac in neutral media. Cyclic voltammetry measurements were conducted to identify diclofenac and determine the kinetics and electrochemical mechanism of its oxidation, along with assessing the surface characteristics of the employed SPEs. Graphene and modified graphene SPEs were explored as nanosensors for this purpose. The surface of the graphene SPE was modified using polyvinylidene fluoride, applied through a drop modification procedure. The morphology of the examined SPEs was observed by means of scanning electron microscope, while the electrolyte (0.1 g of diclofenac per litre of phosphate-buffered solution, pH = 7.4) was analysed using UV-Vis spectroscopy. The results indicate that the studied SPEs exhibit promising potential for the detection of diclofenac. [ABSTRACT FROM AUTHOR]

In recent years, the detection and determination of numerous drugs and pharmaceuticals in various media have become crucial aspects of modern healthcare and environmental management. Among the available sensing techniques, electrochemical methods, particularly those utilising screen-printed electrodes (SPEs) and different portable equipment have emerged as rapid, effective, sensitive, and inexpensive. This study focuses on the detection of the anti-inflammatory drug diclofenac in neutral media. Cyclic voltammetry measurements were conducted to identify diclofenac and determine the kinetics and electrochemical mechanism of its oxidation, along with assessing the surface characteristics of the employed SPEs. Graphene and modified graphene SPEs were explored as nanosensors for this purpose. The surface of the graphene SPE was modified using polyvinylidene fluoride, applied through a drop modification procedure. The morphology of the examined SPEs was observed by means of scanning electron microscope, while the electrolyte (0.1 g of diclofenac per litre of phosphate-buffered solution, pH = 7.4) was analysed using UV-Vis spectroscopy. The results indicate that the studied SPEs exhibit promising potential for the detection of diclofenac.

A plasmonic nanosensor is proposed and investigated its sensitivity using the optical properties of plasmonic nanoparticles. To this end, we first consider the nanosensor consisting of bowtie nanoparticles. Then, the nanosensor performance is examined under different factors such as the refractive index of the background environment, the height, and length of the nanoparticles. The proposed bowtie nanoparticles, in this work, are made of gold. The boundary element method is used to simulate the nanosensor. The extinction cross-section is computed in terms of wavelength and the effect of various factors on the resonance wavelength of localized surface plasmon is investigated. It is shown that the nanosensor investigated in this research has a high sensitivity to the changes in the refractive index of the studied sample. The sensitivity of the nanosensor is obtained as 650 nm/RIIU. In addition, the required spectral range can be arbitrarily adjusted by the type of nanoparticles. [ABSTRACT FROM AUTHOR]

Oxytocin plays a critical role in regulating social behaviors, yet our understanding of its function in both neurological health and disease remains incomplete. Real-time oxytocin imaging probes with spatiotemporal resolution relevant to its endogenous signaling are required to fully elucidate oxytocin's role in the brain. Herein, we describe a near-infrared oxytocin nanosensor (nIROXT), a synthetic probe capable of imaging oxytocin in the brain without interference from its structural analogue, vasopressin. nIROXT leverages the inherent tissue-transparent fluorescence of single-walled carbon nanotubes (SWCNT) and the molecular recognition capacity of an oxytocin receptor peptide fragment to selectively and reversibly image oxytocin. We employ these nanosensors to monitor electrically stimulated oxytocin release in brain tissue, revealing oxytocin release sites with a median size of 3,m in the paraventricular nucleus of C57BL/6 mice, which putatively represents the spatial diffusion of oxytocin from its point of release. These data demonstrate that covalent SWCNT constructs, such as nIROXT, are pow-erful optical tools that can be leveraged to measure neuropeptide release in brain tissue. [ABSTRACT FROM AUTHOR]

In recent years, the deep integration of basic research and clinical translational research of nanotechnology and oncology has led to the emergence of a new branch, namely integrated nanooncology. This is an emerging and important interdisciplinary field, which plays an irreplaceable role in the diagnosis, treatment, early warning, monitoring and prevention of tumors, and has become a new interdisciplinary frontier. Here main advances of integrated nano-oncology was reviewed, mainly included controlled preparation of nanomaterials, ultra-sensitive detection of tumor biomarkers, multifunctional nanoimaging probes and integrated diagnosis and treatment technology, innovative nano drugs and nano drug delivery system, DNA nanotechnology, RNA nanotechnology, nano selfassembly technology, nanosensors, intelligent nanorobots, nanotherapeutic machines. The terms, concepts, trends and challenges are also discussed with the aim of promoting the application of nanotechnology in integrated oncology and solving the scientific and key technical problems in basic and clinical translational research of cancer. [ABSTRACT FROM AUTHOR]

Plant health monitoring is essential for understanding the impact of environmental stressors (biotic and abiotic) on crop production, and for tailoring plant developmental and adaptive responses accordingly. Plants are constantly exposed to different stressors like pathogens and soil pollutants (heavy metals and pesticides) which pose a serious threat to their survival and to human health. Plants have the ability to respond to environmental stressors by undergoing rapid transcriptional, translational, and metabolic reprogramming at different cellular compartments in order to balance growth and adaptive responses. However, plants' exceptional responsiveness to environmental cues is highly complex, which is driven by diverse signaling molecules such as calcium Ca2+, reactive oxygen species (ROS), hormones, small peptides and metabolites. Additionally, other factors like pH also influence these responses. The regulation and occurrence of these plant signaling molecules are often undetectable, necessitating nondestructive, live research approaches to understand their molecular complexity and functional traits during growth and stress conditions. With the advent of sensors, in vivo and in vitro understanding of some of these processes associated with plant physiology, signaling, metabolism, and development has provided a novel platform not only for decoding the biochemical complexity of signaling pathways but also for targeted engineering to improve diverse plant traits. The application of sensors in detecting pathogens and soil pollutants like heavy metal and pesticides plays a key role in protecting plant and human health. In this review, we provide an update on sensors used in plant biology for the detection of diverse signaling molecules and their functional attributes. We also discuss different types of sensors (biosensors and nanosensors) used in agriculture for detecting pesticides, pathogens and pollutants. [ABSTRACT FROM AUTHOR]

Monitoring agricultural toxins such as mycotoxins is crucial for a healthy society. High concentrations of these toxins lead to the cause of several chronic diseases; therefore, developing analytical systems for detecting/monitoring agricultural toxins is essential. These toxins are found in crops such as vegetables, fruits, food, and beverage products. Currently, screening of these toxins is mostly performed with sophisticated instrumentation such as chromatography and spectroscopy techniques. However, these techniques are very expensive and require extensive maintenance, and their availability is limited to metro cities only. Alternatively, electrochemical biomimetic sensing methodologies have progressed hugely during the last decade due to their unique advantages like point-of-care sensing, miniaturized instrumentations, and mobile/personalized monitoring systems. Specifically, affinity-based sensing strategies including immunosensors, aptasensors, and molecular imprinted polymers offer tremendous sensitivity, selectivity, and stability to the sensing system. The current review discusses the principal mechanisms and the recent developments in affinity-based sensing methodologies for the detection and continuous monitoring of mycotoxins and pesticides. The core discussion has mainly focused on the fabrication protocols, advantages, and disadvantages of affinity-based sensing systems and different exploited electrochemical transduction techniques. [ABSTRACT FROM AUTHOR]

Nanotechnology is a multifaceted technical and scientific field undergoing a fast expansion. Nanoparticles, quantum dots, nanotubes, nanorods, nanowires, nanochips and many more are being increasingly used for fabrication of nanosensors and nanobiosensors to increase the sensitivity and selectivity of reactions. Food safety is an extremely important concern in food industries since it is directly associated with effect of food on human health. Here in our review, we have not only described the newest information regarding methods and use of nanomaterials for construction of nanosensors but also their detection range, limit of detection (LOD) and applications for food safety. Precise nanosensors having improved sensitivity and low limit of detection were discussed in brief. Review is primarily focused on nanosensors employed for detection of adulterants and contaminants in food products such as meat products, milk, fruit juices and water samples. [ABSTRACT FROM AUTHOR]

This work reports the development of novel curcuminoid-based electrochemical sensors for the detection of environmental pollutants from water. In this study, the first set of electrochemical experiments was carried out using curcumin-conjugated multi-walled carbon nanotubes (MWCNT–CM) for 1,4-dioxane detection. The MWCNT–CM/GCE showed good sensitivity (103.25 nA nM−1 cm−2 in the linear range 1 nM to 1 µM), with LOD of 35.71 pM and LOQ of 108.21 pM. The second set of electrochemical experiments was carried out with bisdemethoxy curcumin analog quantum dots (BDMCAQD) for hydrazine detection. The BDMCAQD/GCE exhibited good sensitivity (74.96 nA nM−1 cm−2 in the linear range 100 nM to 1 µM), with LOD of 10 nM and LOQ of 44.93 nM. Thus, this work will serve as a reference for the fabrication of metal-free electrochemical sensors using curcuminoids as the redox mediator for the enhanced detection of environmental pollutants. [ABSTRACT FROM AUTHOR]

Biosensors are becoming ubiquitous in the study of biomolecules, as, by modifying shape size and environment of metallic nanostructures it is now possible to engineer the field so to monitor subtle transient changes in molecular conformation at the level of a single biolayer. In this paper, we present a first step towards a polarization-resolved study of light-induced conformational changes of transmembrane proteins. We exploit a platform of self-organized gold nanorods on SiO2 substrates to enhance the infrared reflection absorption spectroscopy and to perform difference spectroscopy (i.e., spectrum under visible light ON minus spectrum under visible light OFF) on a light-sensitive transmembrane protein with simultaneous visible light illumination from the backside of the chip. The broad size distribution of nanorods allows us to probe with high sensitivity the modifications of the vibrational peaks over the entire fingerprint region. We show that it is possible to identify dissimilarities in the difference spectra, which in turn implies that we are monitoring over a broadband spectrum not only the chemical bonds with the dipole moment aligned orthogonally to our substrate/nanorod surface but also those with different orientation. [ABSTRACT FROM AUTHOR]

The advanced and highly functional properties of Al2O3 and NiO nanoparticles promote the widespread use of metal oxides as remarkable electroactive materials for sensing and electrochemical applications. The proposed study describes a comparison of the sensitivity and selectivity of two modified wire membrane sensors enriched with Al2O3 and NiO nanoparticles with conventional wire membranes for the quantification of the antidiabetic drug metformin hydrochloride (MTF). The results show linear relationships of the enriched Al2O3 and NiO nanosensors over the concentration ranges 1.0 × 10−10–1.0 × 10−2 mol L−1 and 1.0 × 10−6–1.0 × 10−2 M for both the modified sensors and the conventional coated wire membrane sensors. The regression equations were E mV = (52.1 ± 0.5) log (MTF) + 729 for enriched nanometallic oxides, E mV = (57.04 ± 0.4) log (MTF) + 890.66, and E mV = (58.27 ± 0.7) log (MTF) + 843.27 with correlation coefficients of 0.9991, 0.9997, and 0.9998 for the aforementioned sensors, respectively. The proposed method was fully validated with respect to the recommendations of the International Union of Pure and Applied Chemistry (IUPAC). The newly functionalized sensors have been successfully used for the determination of MTF in its commercial products. [ABSTRACT FROM AUTHOR]