On-site Screening Research Articles

Sensitive Immunochromatographic Assay (ICA) for the Determination of Thiamethoxam in Fruit, Vegetables, and Natural Water

Rapid on-site detection of thiamethoxam, a widely used neonicotinoid insecticide, is required to ensure food safety and environmental health. In this study, we produced specific and high-affinity monoclonal antibodies against thiamethoxam and developed an immunochromatographic assay (ICA) strip. Monoclonal antibodies labeled with colloidal gold particles were used as the probe, nitrocellulose membrane as the solid carrier, thiamethoxam-ovalbumin (OVA) conjugate as the test line, and goat anti-rat immunoglobulin G (IgG) as the control line. The visual limit of detection of the test strip was 0.5 µg/L thiamethoxam and the cutoff value was 2.0 µg/L. The test strip enabled rapid visual detection (within 10 min) of thiamethoxam. Matrix interferences were eliminated by diluting the sample extracts with the optimized working buffer solution (phosphate buffer containing 5% methanol v/v, pH 8.0); the final dilutions used were: 50-fold for cucumber, pear, and bok choy extracts, 5-fold for apple extracts, and 2-fold for pond water. Using the recovery test, we verified that the test strip was suitable for rapid on-site determination of thiamethoxam residues in fruit, vegetable, and water samples. The developed immunochromatographic assay is easy to use, rapid, environment-friendly, and suitable for on-site screening and detection of thiamethoxam residues in food and environmental samples.

Colorimetric test strip cassette readout with a smartphone for on-site and rapid screening test of carbamate pesticides in vegetables

A test strip cassette integrated with a smartphone detector was developed for the colorimetric detection of carbamate pesticides in vegetables. The influence of various experimental conditions was examined for the detection of the optimum analytical performance of the test strip cassette. The test strip cassette detection of carbamate pesticides was carried out by using 140 mM of acetylthiocholine, 13 mM of 5,5′-dithiobis (2-nitrobenzoic acid), temperature at 37 °C and pH of 8.0. The developed test strip cassette platform is rapid within 5 min. Based on the inhibition effect of carbaryl on acetylcholinesterase activity, the inhibition effect of carbaryl was proportional to its concentration ranging from 1 to 50 mg/L with the detection limit of 0.30 mg/L. The limit of quantitative value was determined to be 1.0 mg/L. The spiking carbaryl, the recoveries were within 96–103% and the relative standard deviations were less than 1.56%. The analysis of carbamate pesticides residual in vegetable samples gave the results in good agreement with the most widely used commercial test kit and UPLC-MS/MS method. The developed test strip cassette required only 5 min for an assay. With the simple procedures and tiny size, it showed a great promising for the developed test strip to work on-site for carbamate pesticides detection in vegetables.

Deep learning and machine learning-based voice analysis for the detection of COVID-19: A proposal and comparison of architectures

Alongside the currently used nasal swab testing, the COVID-19 pandemic situation would gain noticeable advantages from low-cost tests that are available at any-time, anywhere, at a large-scale, and with real time answers. A novel approach for COVID-19 assessment is adopted here, discriminating negative subjects versus positive or recovered subjects. The scope is to identify potential discriminating features, highlight mid and short-term effects of COVID on the voice and compare two custom algorithms. A pool of 310 subjects took part in the study; recordings were collected in a low-noise, controlled setting employing three different vocal tasks. Binary classifications followed, using two different custom algorithms. The first was based on the coupling of boosting and bagging, with an AdaBoost classifier using Random Forest learners. A feature selection process was employed for the training, identifying a subset of features acting as clinically relevant biomarkers. The other approach was centered on two custom CNN architectures applied to mel-Spectrograms, with a custom knowledge-based data augmentation. Performances, evaluated on an independent test set, were comparable: Adaboost and CNN differentiated COVID-19 positive from negative with accuracies of 100% and 95% respectively, and recovered from negative individuals with accuracies of 86.1% and 75% respectively. This study highlights the possibility to identify COVID-19 positive subjects, foreseeing a tool for on-site screening, while also considering recovered subjects and the effects of COVID-19 on the voice. The two proposed novel architectures allow for the identification of biomarkers and demonstrate the ongoing relevance of traditional ML versus deep learning in speech analysis.

Rapid and universal detection of SARS-CoV-2 and influenza A virus using a reusable dual-channel optic fiber immunosensor.

Establishment of rapid on‐site detection technology capable of concurrently detecting SARS‐Cov‐2 and influenza A virus is urgent to effectively control the epidemic from these two types of important viruses. Accordingly, we developed a reusable dual‐channel optical fiber immunosensor (DOFIS), which utilized the evanescent wave‐sensing properties and tandem detection mode of the mobile phase, effectively accelerating the detection process such that it can be completed within 10 min. It could detect the nucleoprotein of multiple influenza A viruses (H1N1, H3N2, and H7N9), as well as the spike proteins of the SARS‐CoV‐2 Omicron and Delta variants, and could respond to 20 TCID50/ml SARS‐CoV‐2 pseudovirus and 100 TCID50/ml influenza A (A/PR/8/H1N1), presenting lower limit of detection and wider linear range than enzyme‐linked immunosorbent assay. The detection results on 26 clinical samples for SARS‐CoV‐2 demonstrated its specificity (100%) and sensitivity (94%), much higher than the sensitivity of commercial colloidal gold test strip (35%). Particularly, DOFIS might be reused more than 80 times, showing not only cost‐saving but also potential in real‐time monitoring of the pathogenic viruses. Therefore, this newly‐developed DOFIS platform is low cost, simple to operate, and has broad spectrum detection capabilities for SARS‐CoV‐2 mutations and multiple influenza A strains. It may prove suitable for deployment as a rapid on‐site screening and surveillance technique for infectious disease.

FRI312 - Awareness of chronic hepatitis B and C among men who have sex with men (MSM): epidemiological survey and on-site screening

FRI312 - Awareness of chronic hepatitis B and C among men who have sex with men (MSM): epidemiological survey and on-site screening

Utilizing Electrochemical-Based Sensing Approaches for the Detection of SARS-CoV-2 in Clinical Samples: A Review.

The development of precise and efficient diagnostic tools enables early treatment and proper isolation of infected individuals, hence limiting the spread of coronavirus disease 2019 (COVID-19). The standard diagnostic tests used by healthcare workers to diagnose severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection have some limitations, including longer detection time, the need for qualified individuals, and the use of sophisticated bench-top equipment, which limit their use for rapid SARS-CoV-2 assessment. Advances in sensor technology have renewed the interest in electrochemical biosensors miniaturization, which provide improved diagnostic qualities such as rapid response, simplicity of operation, portability, and readiness for on-site screening of infection. This review gives a condensed overview of the current electrochemical sensing platform strategies for SARS-CoV-2 detection in clinical samples. The fundamentals of fabricating electrochemical biosensors, such as the chosen electrode materials, electrochemical transducing techniques, and sensitive biorecognition molecules, are thoroughly discussed in this paper. Furthermore, we summarised electrochemical biosensors detection strategies and their analytical performance on diverse clinical samples, including saliva, blood, and nasopharyngeal swab. Finally, we address the employment of miniaturized electrochemical biosensors integrated with microfluidic technology in viral electrochemical biosensors, emphasizing its potential for on-site diagnostics applications.

A Rapid Tricolour Immunochromatographic Assay for Simultaneous Detection of Tricaine and Malachite Green.

In this research, we designed a rapid tricolour immunochromatographic test strip with double test lines (TS-DTL) and two-colour AuNP probes, which realised the simultaneous detection of tricaine mesylate (TMS) and malachite green (MG). Through a distinct tricolour system (red T1 line, blue T2 line and purple C line), a visual identification of TMS (0.2 μg/mL) and MG (0.5 μg/mL) was quickly achieved on site, which improved the accuracy of naked eye observations. The LODs of TMS in aquaculture water, fish and shrimp were 11.0, 29.6 and 61.4 ng/mL, respectively. MG LODs were 47.0 ng/mL (aquaculture water), 82.8 ng/mL (fish) and 152.4 ng/mL (shrimp). The LOD of MG was close to the similar TS methods. However, visual detection of TMS could meet the requirements of the residue limit (1 μg/mL) of TMS in the USA, and the quantitative detection of TMS was over 16 times lower than the USA standard. The developed platform was rapid (~20 min, HPLC~3 h) and accurate, which was verified using a traditional HPLC method. The recovery rates ranged from 82.2% to 108.6% in three types of real samples, indicating a potential application in on-site fast screening or multiple detection for TMS and MG residues in aquatic products.

An electrochemical sensor based on cobalt oxyhydroxide nanoflakes/reduced graphene oxide nanocomposite for detection of illicit drug-clonazepam

Clonazepam (CNZ) is a commonly prescribed drug for the management of mental illness including insomnia, panic anxiety and status epilepsy. Due to the associated sedative effects, CNZ has also become a drug of abuse amongst addicted users, sexual assault cases, and suicide. Therefore, it becomes vital to analyze CNZ in human specimens for criminal investigational purposes. Herein, we report the construction of an electrochemical sensor based on self-assembled hybrid nanocomposite of 2-D transition metal oxide nanoflakes i.e., cobalt oxyhydroxide (CoOOH) nanoflakes and reduced graphene oxide (rGO) for determination of clonazepam (CNZ), especially in different beverages. The physico-chemical characterization of the as-synthesized hybrid nanocomposite was done by scanning electron microscopy (SEM), X-Ray diffraction (XRD), raman spectroscopy, X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR) and UV–Visible spectroscopy. Further, the surface of the screen printed carbon electrode (SPCE) was modified with CoOOH-rGO hybrid nanocomposite and its electrochemical characteristics were evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. A synergistic combination of CoOOH nanoflakes with abundant catalytic sites and highly supportive skeletons of rGO nanosheets that act as conductive bridges for charge transfer makes the nanocomposite sensor unique for electrochemical detection. Under optimized conditions, the specific interaction of CNZ with CoOOH-rGO modified SPCE was determined by differential pulse voltammetry (DPV) to measure the dose dependent increase in reduction current values at a potential of 0.11 V. The developed sensor achieved a detection limit of 38 nM with a sensitivity of 0.054 µA µM−1 cm−2 over a dynamic concentration range of 0.1–350 µM. Moreover, the sensor was applied for determination of CNZ in spiked beverages samples and showed satisfactory recovery in the range of 87–115%. This work provides a new avenue for the development of hybrid nanocomposites based electrochemical sensing platforms for on-site screening of illicit drugs, as necessitated for forensics and clinical settings.

Inkjet-printed colorimetric sensor array for the rapid identification of adulterated Fritillariae cirrhosae bulbus

As an important antitussive and expectorant herbal medicine, Fritillariae cirrhosae bulbus (FCB) is rare and expensive, leading to massive adulterations in the market. Herein, we report a solid colorimetric sensor array (CSA) method for the rapid identification of FCB and its adulterations. This CSA was fabricated by printing nine pH indicators on a mixed cellulose ester membrane via a commercially available inkjet printer filled with polyethylene glycol-containing ink. This CSA displayed color changes to various analytes, as their solution of varied pH values triggers chemical reactions with the nine pH indicators (and other potential interactions). The digital database of these colorimetric response patterns was collected automatically using a homemade program. The outstanding identification capability of the CSA was confirmed via the analysis of 1,2-diols and catechols. The principal component analysis result demonstrated that this CSA could distinguish pure FCB powder from its six common adulterations. The linear discriminant analysis models were established for the qualitative identification of adulterated FCB samples with 89.58 %− 100 % accuracy. Furthermore, partial least squares regression models were developed for the quantitation of adulterant percentages with correlation coefficients higher than 0.87. We expect that the inkjet-printed CSA provided an effective on-site screening method for identifying adulterated FCB.

Polyamidoxime-based membranes for the rapid screening of uranium isotopes in water

Traditional radiochemistry approaches for the detection of trace-level alpha-emitting radioisotopes in water require lengthy offsite sample preparations and do not lend themselves to rapid quantification. Therefore, a novel platform is needed that combines onsite purification, concentration, and isotopic screening with a fieldable detection system. This contribution describes the synthesis and characterization of polyamidoxime membranes for isolation and concentration of uranium from aqueous matrices, including high-salinity seawater. The aim was to develop a field portable screening method for the rapid quantification of isotopic distribution by alpha spectroscopy. Membranes with varying degree of modification were prepared by chemical conversion of nitrile groups to amidoxime groups on the surface of polyacrylonitrile ultrafiltration (UFPAN) membranes. Attenuated total reflectance Fourier-transform infrared spectroscopy was used to analyze changes in surface chemistry. Flow through filtration experiments conducted using deionized (DI) water and simulated seawater solutions indicated that the modified membrane was effective in capturing more than 95% of the uranium in the solution prior to breakthrough even in the presence of salt ions. Batch uptake experiments were conducted and compared with the flow through experimental data to elucidate likely binding mechanisms. Alpha spectra of uranium loaded membranes were analyzed, and the effects of solution matrix and degree of modification on peak energy resolution were studied. Peak energy resolutions of 24 ± 2 keV and 32 ± 6 keV full width at half maximum (FWHM) were obtained by loading uranium from DI and seawater solutions onto modified membranes. Full width at 10% maximum of the same spectra were calculated to be 63 ± 9 keV and 160 ± 34 keV to quantify differences seen in peak tailing. Calculations performed based on the results show that it would take less than 3 h of analysis time to screen a sample provided enough volumes of solution are available. This work offers a facile method to prepare polyamidoxime-based membranes for uranium separation and concentration at circumneutral pH values, enabling the rapid, onsite screening of unknown samples.

Profiling of grazed cultures of the chlorophyte alga Dunaliella tertiolecta using an untargeted LC-MS approach.

Extracellular signals are reported to mediate chemical cross-talk among pelagic microbes, including microalgal prey and predators. Water-soluble mediator compounds play a crucial role in extracellular communication which is vital for prey recognition, attraction, capture, and predator deterrence. A range of exo-metabolites including oxylipins and vitamins are released by prey in response to grazing stress. The temporal dynamics of such exo-metabolites largely remains unknown, especially in large-scale cultivation of microalgae such as closed or open ponds. In open ponds, infestation of predators is almost inevitable but highly undesirable due to the imminent threat of culture collapse. The early production of exo-metabolites emitted by microalgal prey in response to predator attack could be leveraged as diagnostic markers of possible culture collapse. This study uses an untargeted approach for temporal profiling of Dunaliella tertiolecta-specific exo-metabolites under grazing pressure from Oxyrrhis marina. We report 24 putatively identified metabolites, belonging to various classes such as short peptides, lipids, indole-derivatives, and free amino acids, as potential markers of grazing-mediated stress. In addition, this study outlines a clear methodology for screening of exo-metabolites in marine algal samples, the analysis of which is frequently hindered by high salt concentrations. In future, a chemistry-based targeted detection of these metabolites could enable a quick and on-site screening of predators in microalgal cultures.

Quantitative and ultrasensitive in situ immunoassay technology for SARS-CoV-2 detection in saliva.

The coronavirus disease 2019 (COVID-19) pandemic has become an immense global health crisis. However, the lack of efficient and sensitive on-site testing methods limits early detection for timely isolation and intervention. Here, we present a quantitative and ultrasensitive in situ immunoassay technology for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection in saliva (QUIT SARS-CoV-2). Our nanoporous membrane resonator generates a rapid oscillating flow to purify and concentrate fully intact SARS-CoV-2 virus in saliva by 40-fold for in situ detection of viral antigens based on chemiluminescent immunoassay within 20 min. This method can not only achieve a detection sensitivity below 100 copies/ml of virus, comparable to the bench-top PCR equipment; it can also improve detection specificity via direct monitoring of viral loads. The integrated portable QUIT SARS-CoV-2 system, which enables rapid and accurate on-site viral screening with a high-throughput sample pooling strategy, can be performed in primary care settings and substantially improve the detection and prevention of COVID-19.

Cerium oxide-doped PEDOT nanocomposite for label-free electrochemical immunosensing of anti-p53 autoantibodies.

Alabel-free nanoimmunosensor is reportedbased on p53/CeO2/PEDOT nanobiocomposite-decorated screen-printed gold electrodes (SPAuE) for the electrochemical detection of anti-p53 autoantibodies. CeO2 nanoparticles (NPs) were synthesized and stabilized with cyanopropyltriethoxysilane by a soft chemistry method. The nanoimmunosensing architecture was prepared by in situ electropolymerization of 3,4-ethylenedioxythiophene (EDOT) on SPAuE in the presence of CeO2 NPs. The CeO2 NPs and Ce/PEDOT/SPAuE were characterized by scanning and transmission electron microscopy, dynamic and electrophoretic light scattering, ultraviolet-visible spectrophotometry, X-ray diffraction, Fourier-transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Ce/PEDOT/SPAuE was biofunctionalized with p53 antigen by covalent bonding for the label-free determination of anti-p53 autoantibodies by differential pulse voltammetry. The nanobiocomposite-based nanoimmunosensor detected anti-p53 autoantibodies in a linear range from 10 to 1000pgmL-1, with a limit of detection (LOD) of 3.2pgmL-1. The nanoimmunosensor offered high specificity, selectivity, and long-term storage stability with great potential to detect anti-p53 autoantibodies in serum samples. Overall, incorporating organo-functional nanoparticles into polymeric matrices can provide a simple-to-assemble, rapid, and ultrasensitive approach for on-site screening of anti-p53 autoantibodies and other disease-related biomarkers with low sample volumes.

One-step ultra-sensitive immunochromatographic strip authenticating an emergent fraud acetophenetidin in herbal tea

Herbal tea is a highly popular and widely consumed beverage. However, a pain-relieving and fever-reducing drug, acetophenetidin, was recently found to illegally occur in herbal tea for a fraud purpose. Due to the potential health risk and urgent requirement for on-site screening method, a one-step and high specificity strip for identifying acetophenetidin was developed for the first time. Assisted by computational chemistry, four haptens were designed to prepare immunogens and coating antigens for antibody generation, and a specific antibody with ultra-sensitivity and high specificity was generated, showing half maximal inhibitory (IC50) of 16.46 ng/mL for acetophenetidin, less than 3.5% of cross-reactivity to analogs by ELISA. A gold nanoparticles immunochromatographic strip was developed for detection of acetophenetidin in herbal tea, demonstrating a cut-off value of 160 ng/mL and a limit of detection of 1.63 ng/mL. The recovery rates were ranged from 102.2% to 106.1% with coefficient of variation between 2.21% and 7.20%. The analysis of real samples (n = 20) by the strip was well correlated with that of the confirmatory method, liquid chromatography−tandem mass spectrometry. The proposed strip has the potential to be used for rapid screening of acetophenetidin in herbal tea.

Ultrasensitive detection of four organic arsenic compounds at the same time using a five-link cardboard-based assay

In order to effectively control the excessive use of organic arsenic reagents in livestock and poultry products, there is an urgent need to develop a method for rapid detection of multiple organic arsenic reagents. In this study, two haptens were designed and derivatized around the structural formula of roxarsone, and a highly-sensitive group-selective mAb 3F2 was prepared, which can simultaneously detect roxarsone, 4-aminophenylarsonic acid, 2-aminophenylarsonic acid and phenylarsonic acid. We further developed a colloidal gold immunochromatographic test strip (ICS) and prepared a five-link card that can simultaneously detect four organic arsenics in chicken and pork samples. Its quantitative detection limits (LOQ) for the four compounds in chicken and pork samples were 0.06 and 0.32 ng/mL, 0.11 and 0.29 ng/mL, 0.34 and 0.99 ng/mL, and 0.88 and 1.5 ng/mL, respectively. This multi-ICS detection provides a powerful tool for the on-site detection and rapid screening of organic arsenic reagents in actual samples.

Real-time electrochemical screening of cocaine in lab and field settings with automatic result generation.

This work presents the results of a novel application for the fast on-site screening of cocaine and its main cutting agents in suspicious and confiscated samples. The methodology behind the novel application consists of portable electrochemical detection coupled with a peak recognition algorithm for automated result output generation, validated both in laboratory and field settings. Currently used field tests, predominantly colorimetric tests, are lacking accuracy, often giving false positive or negative results. This presses the need for alternative approaches to field testing. By combining portable electrochemical approaches with peak recognition algorithms, an accuracy of 98.4% concerning the detection of cocaine was achieved on a set of 374 powder samples. In addition, the approach was tested on multiple "smuggled," colored cocaine powders and cocaine mixtures in solid and liquid states, typically in matrices such as charcoal, syrup, and clothing. Despite these attempts to hide cocaine, our approach succeeded in detecting cocaine during on-site screening scenarios. This feature presents an advantage over colorimetric and optical detection techniques, which can fail with colored sample matrices. This enhanced accuracy on smuggled samples will lead to increased efficiency in confiscation procedures in the field, thus significantly reducing societal economic and safety concerns and highlighting the potential for electrochemical approaches in on-the-spot identification of drugs of abuse.

On-site magnetic screening tool for rapid detection of hospital bacterial infections: Clinical study with Klebsiella pneumoniae cells

The high numbers of mortality related to drug-resistant bacterial superbugs have highlighted the need for rapid, highly sensitive, and cost-effective screening tools, ideally in seamless and point-of-need format. Herein, we report a portable in-flow magnetic transduction-based instrument capable of rapid and highly sensitive detection of whole-bacterial cells in complex matrices. Magnetoresistive (GMR) sensors are combined with microfluidic channels and interfaced with a low noise electronic architecture. The attained practical read-out allows for the interrogation of flowing samples containing small target biological entities (<5 μm). As a proof-of-concept, the device was first optimized for the detection of Klebsiella pneumoniae cells in laboratory samples, demonstrating a 100% sensitivity and 80.8% specificity. Further testing with clinical rectal swabs collected from 40 patients admitted to the hospital emergency department has unveiled its capability for bacteria detection in highly complex matrices with 100% sensitivity, without the need for a pre-enrichment step. Despite some false positives, a screening tool for such application greatly depends on its capacity to correctly identify all positive cases with proper isolation of suspected patients. The test provides a result after 20 min of exposure to 100 μL of sample volume. The magnetic device is a highly flexible tool, being easily customized to detect other bacterial species whenever a corresponding specific recognition ligand is available.

Establishment and evaluation of qPCR and real-time recombinase-aided amplification assays for detection of largemouth bass ranavirus.

Largemouth bass ranavirus disease (LMBVD) caused by largemouth bass ranavirus (LMBV) has resulted in severe economic losses in the largemouth bass (Micropterus salmoides) farming industry in China. Early and accurate diagnosis is the key measure for the prevention and control of LMBVD. In this study, a quantitative polymerase chain reaction (qPCR) and a real-time recombinase-aided amplification (real-time RAA) assay were established for the detection of LMBV. The sensitivity and specificity of these two methods, and the efficacy for detection of LMBV from clinical samples were also evaluated. Results showed that the real-time RAA reaction was completed in <30min at 39℃ with a detection limit of 58.3 copies, while qPCR reaction required 60min with a detection limit of 5.8 copies. Both methods were specific for LMBV, where no cross-reactions observed with the other tested fish pathogens. Comparing the amplification results of both assays to the results obtained by virus isolation using 53 clinical tissue samples, results showed that the clinical sensitivity of real-time RAA and qPCR were 93.75% and 100% respectively, and the clinical specificity of both were 100%. Our results showed that qPCR is more suitable for quantitative analysis and accurate detection of LMBV in the laboratory, while real-time RAA is more suitable as a point-of-care diagnostic tool for on-site detection and screening of LMBV under farm conditions and in poorly equipped laboratories.

Paraformaldehyde-coated electrochemical sensor for improved on-site detection of amphetamine in street samples

The increasing illicit production, distribution and abuse of amphetamine (AMP) poses a challenge for law enforcement worldwide. To effectively combat this issue, fast and portable tools for the on-site screening of suspicious samples are required. Electrochemical profile (EP)-based sensing of illicit drugs has proven to be a viable option for this purpose as it allows rapid voltammetric measurements via the use of disposable and low-cost graphite screen-printed electrodes (SPEs). In this work, a highly practical paraformaldehyde (PFA)-coated sensor, which unlocks the detectability of primary amines through derivatization, is developed for the on-site detection of AMP in seized drug samples. A potential interval was defined at the sole AMP peak (which is used for identification of the target analyte) to account for potential shifts due to fluctuations in concentration and temperature, which are relevant factors for on-site use. Importantly, it was found that AMP detection was not hindered by the presence of common diluents and adulterants such as caffeine, even when present in high amounts. When inter-drug differentiation is desired, a simultaneous second test with the same solution on an unmodified electrode is introduced to provide the required additional electrochemical information. Finally, the concept was validated by analyzing 30 seized AMP samples (reaching a sensitivity of 96.7 %) and comparing its performance to that of commercially available Raman and Fourier Transform Infrared (FTIR) devices.

Bioanalytical approaches for the detection, characterization, and risk assessment of micro/nanoplastics in agriculture and food systems.

This review discusses the most recent literature (mostly since 2019) on the presence and impact of microplastics (MPs, particle size of 1μm to 5mm) and nanoplastics (NPs, particle size of 1 to 1000nm) throughout the agricultural and food supply chain, focusing on the methods and technologies for the detection and characterization of these materials at key entry points. Methods for the detection of M/NPs include electron and atomic force microscopy, vibrational spectroscopy (FTIR and Raman), hyperspectral (bright field and dark field) and fluorescence imaging, and pyrolysis-gas chromatography coupled to mass spectrometry. Microfluidic biosensors and risk assessment assays of MP/NP for in vitro, in vivo, and in silico models have also been used. Advantages and limitations of each method or approach in specific application scenarios are discussed to highlight the scientific and technological obstacles to be overcome in future research. Although progress in recent years has increased our understanding of the mechanisms and the extent to which MP/NP affects health and the environment, many challenges remain largely due to the lack of standardized and reliable detection and characterization methods. Most of the methods available today are low-throughput, which limits their practical application to food and agricultural samples. Development of rapid and high-throughput field-deployable methods for onsite screening of MP/NPs is therefore a high priority. Based on the current literature, we conclude that detecting the presence and understanding the impact of MP/NP throughout the agricultural and food supply chain require the development of novel deployable analytical methods and sensors, the combination of high-precision lab analysis with rapid onsite screening, and a data hub(s) that hosts and curates data for future analysis.