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1.
Anal Chim Acta ; 1312: 342761, 2024 Jul 11.
Article En | MEDLINE | ID: mdl-38834276

BACKGROUND: Diabetes is a significant health threat, with its prevalence and burden increasing worldwide indicating its challenge for global healthcare management. To decrease the disease severity, the diabetic patients are recommended to regularly check their blood glucose levels. The conventional finger-pricking test possesses some drawbacks, including painfulness and infection risk. Nowadays, smartphone has become a part of our lives offering an important benefit in self-health monitoring. Thus, non-invasive wearable sweat glucose sensor connected with a smartphone readout is of interest for real-time glucose detection. RESULTS: Wearable sweat glucose sensing device is fabricated for self-monitoring of diabetes. This device is designed as a body strap consisting of a sensing strip and a portable potentiostat connected with a smartphone readout via Bluetooth. The sensing strip is modified by carbon nanotubes (CNTs)-cellulose nanofibers (CNFs), followed by electrodeposition of Prussian blue. To preserve the activity of glucose oxidase (GOx) immobilized on the modified sensing strip, chitosan is coated on the top layer of the electrode strip. Herein, machine learning is implemented to correlate between the electrochemical results and the nanomaterial content along with deposition cycle of prussian blue, which provide the highest current response signal. The optimized regression models provide an insight, establishing a robust framework for design of high-performance glucose sensor. SIGNIFICANCE: This wearable glucose sensing device connected with a smartphone readout offers a user-friendly platform for real-time sweat glucose monitoring. This device provides a linear range of 0.1-1.5 mM with a detection limit of 0.1 mM that is sufficient enough for distinguishing between normal and diabetes patient with a cut-off level of 0.3 mM. This platform might be an alternative tool for improving health management for diabetes patients.


Biosensing Techniques , Diabetes Mellitus , Machine Learning , Smartphone , Sweat , Wearable Electronic Devices , Humans , Sweat/chemistry , Biosensing Techniques/instrumentation , Diabetes Mellitus/diagnosis , Glucose/analysis , Nanotubes, Carbon/chemistry , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Electrochemical Techniques/instrumentation
2.
Mikrochim Acta ; 191(6): 362, 2024 06 01.
Article En | MEDLINE | ID: mdl-38822867

Rapid and accurate in situ determination of dopamine is of great significance in the study of neurological diseases. In this work, poly (3,4-ethylenedioxythiophene): poly (styrenesulfonic acid) (PEDOT: PSS)/graphene oxide (GO) fibers were fabricated by an effective method based on microfluidic wet spinning technology. The composite microfibers with stratified and dense arrangement were continuously prepared by injecting PEDOT: PSS and GO dispersion solutions into a microfluidic chip. PEDOT: PSS/GO fiber microelectrodes with high electrochemical activity and enhanced electrochemical oxidation activity of dopamine were constructed by controlling the structure composition of the microfibers with varying flow rate. The fabricated fiber microelectrode had a low detection limit (4.56 nM) and wide detection range (0.01-8.0 µM) for dopamine detection with excellent stability, repeatability, and reproducibility. In addition, the PEDOT: PSS/GO fiber microelectrode prepared was successfully used for the detection of dopamine in human serum and PC12 cells. The strategy for the fabrication of multi-component fiber microelectrodes is a new and effective approach for monitoring the intercellular neurotransmitter dopamine and has high potential as an implantable neural microelectrode.


Dopamine , Graphite , Microelectrodes , Polystyrenes , PC12 Cells , Dopamine/blood , Humans , Rats , Animals , Polystyrenes/chemistry , Graphite/chemistry , Limit of Detection , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Bridged Bicyclo Compounds, Heterocyclic/chemistry , Thiophenes/chemistry , Lab-On-A-Chip Devices , Polymers
3.
Mikrochim Acta ; 191(6): 361, 2024 06 01.
Article En | MEDLINE | ID: mdl-38822891

A one-shot CO2 laser-based strategy to generate conductive reduced graphene oxide (rGO) decorated with nanoceria (nCe) is proposed. The 2D/0D rGO-nCe films, integrated as catalytic sensing layers in paper-based sensors, were employed for on-site monitoring of indoor fogging treatments against Listeria monocytogenes (Lm), a ubiquitous pathogenic bacterium. The rGO-nCe laser-assisted synthesis was optimized to preserve the rGO film morphological and electron-transfer features and simultaneously integrate catalytic nCe. The films were characterized by microscopical (SEM), spectroscopical (EDX, Raman, and FTIR), and electrochemical techniques. The most performing film was integrated into a nitrocellulose substrate, and the complete sensor was assembled via a combination of xurography and stencil printing. The rGO-nCe sensor's catalytic activity was proved toward the detection of H2O2, obtaining sensitive determination (LOD = 0.3 µM) and an extended linear range (0.5-1500 µM). Eventually, the rGO-nCe sensor was challenged for the real-time continuous monitoring of hydrogen peroxide aerosol during no-touch fogging treatment conducted following the EU's recommendation for biocidal product use. Treatment effectiveness was proved toward three Lm strains characterized by different origins, i.e., type strain ATCC 7644, clinical strain 338, and food strain 641/6II. The sensor allows for discrimination and quantification treatments at different environmental biocidal amounts and fogging times, and correlates with the microbiological inhibition, promoting the proposed sensor as a useful tool to modulate and monitor no-touch treatments.


Disinfection , Graphite , Hydrogen Peroxide , Lasers , Listeria monocytogenes , Paper , Graphite/chemistry , Hydrogen Peroxide/chemistry , Listeria monocytogenes/drug effects , Listeria monocytogenes/isolation & purification , Disinfection/methods , Cerium/chemistry , Limit of Detection , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Catalysis
4.
Mikrochim Acta ; 191(6): 309, 2024 05 07.
Article En | MEDLINE | ID: mdl-38714599

Copper-doped carbon dots and aminated carbon nanotubes (Cu-CDs/NH2-CNTs) nanocomposites were synthesized by a one-step growth method, and the composites were characterized for their performance. An electrochemical sensor for sensitive detection of bisphenol A (BPA) was developed for using Cu-CDs/NH2-CNTs nanocomposites modified with glassy carbon electrodes (GCE). The sensor exhibited an excellent electrochemical response to BPA in 0.2 M PBS (pH 7.0) under optimally selected conditions. The linear range of the sensor for BPA detection was 0.5-160 µM, and the detection limit (S/N = 3) was 0.13 µM. Moreover, the sensor has good interference immunity, stability and reproducibility. In addition, the feasibility of the practical application of the sensor was demonstrated by the detection of BPA in bottled drinking water and Liu Yang River water.


Benzhydryl Compounds , Copper , Electrochemical Techniques , Electrodes , Limit of Detection , Nanotubes, Carbon , Phenols , Water Pollutants, Chemical , Benzhydryl Compounds/analysis , Phenols/analysis , Phenols/chemistry , Nanotubes, Carbon/chemistry , Copper/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Water Pollutants, Chemical/analysis , Drinking Water/analysis , Quantum Dots/chemistry , Carbon/chemistry , Rivers/chemistry
5.
Mikrochim Acta ; 191(6): 328, 2024 05 14.
Article En | MEDLINE | ID: mdl-38743383

The instant screening of patients with a tendency towards developing Alzheimer's disease (AD) is significant for providing preventive measures and treatment. However, the current imaging-based technology cannot meet the requirements in the early stage. Developing biosensor-based liquid biopsy technology could be overcoming this bottleneck problem. Herein, we developed a simple, low-cost, and sensitive electrochemical aptamer biosensor for detecting phosphorylated tau protein threonine 231 (P-tau231), the earliest and one of the most efficacious abnormally elevated biomarkers of AD. Gold nanoparticles (AuNPs) were electrochemically synthesized on a glassy carbon electrode as the transducer, exhibiting excellent conductivity, and were applied to amplify the electrochemical signal. A nucleic acid aptamer was designed as the receptor to capture the P-tau231 protein, specifically through the formation of an aptamer-antigen complex. The proposed biosensor showed excellent sensitivity in detecting P-tau 231, with a broad linear detection range from 10 to 107 pg/mL and a limit of detection (LOD) of 2.31 pg/mL. The recoveries of the biosensor in human serum ranged from 97.59 to 103.26%, demonstrating that the biosensor could be used in complex practical samples. In addition, the results showed that the developed biosensor has good repeatability, reproducibility, and stability, which provides a novel method for the early screening of AD.


Alzheimer Disease , Aptamers, Nucleotide , Biosensing Techniques , Electrochemical Techniques , Gold , Limit of Detection , Metal Nanoparticles , tau Proteins , Humans , Alzheimer Disease/blood , Alzheimer Disease/diagnosis , Aptamers, Nucleotide/chemistry , tau Proteins/blood , Biosensing Techniques/methods , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Gold/chemistry , Metal Nanoparticles/chemistry , Phosphorylation , Biomarkers/blood
6.
Biosens Bioelectron ; 258: 116315, 2024 Aug 15.
Article En | MEDLINE | ID: mdl-38701536

Research in electrochemical detection in lateral flow assays (LFAs) has gained significant momentum in recent years. The primary impetus for this surge in interest is the pursuit of achieving lower limits of detection, especially given that LFAs are the most widely employed point-of-care biosensors. Conventionally, the strategy for merging electrochemistry and LFAs has centered on the superposition of screen-printed electrodes onto nitrocellulose substrates during LFA fabrication. Nevertheless, this approach poses substantial limitations regarding scalability. In response, we have developed a novel method for the complete integration of reduced graphene oxide (rGO) electrodes into LFA strips. We employed a CO2 laser to concurrently reduce graphene oxide and pattern nitrocellulose, exposing its backing to create connection sites impervious to sample leakage. Subsequently, rGO and nitrocellulose were juxtaposed and introduced into a roll-to-roll system using a wax printer. The exerted pressure facilitated the transfer of rGO onto the nitrocellulose. We systematically evaluated several electrochemical strategies to harness the synergy between rGO and LFAs. While certain challenges persist, our rGO transfer technology presents compelling potential for setting a new standard in electrochemical LFA fabrication.


Biosensing Techniques , Electrochemical Techniques , Electrodes , Graphite , Point-of-Care Systems , Graphite/chemistry , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Humans , Equipment Design , Collodion/chemistry , Point-of-Care Testing , Limit of Detection , Oxidation-Reduction
7.
Biosens Bioelectron ; 258: 116354, 2024 Aug 15.
Article En | MEDLINE | ID: mdl-38723331

Real-time monitoring of biological markers in sweat is a valuable tool for health assessment. In this study, we have developed an innovative wearable biosensor for precise analysis of glucose in sweat during physical activities. The sensor is based on a single-atom catalyst of platinum (Pt) uniformly dispersed on tricobalt tetroxide (Co3O4) nanorods and reduced graphene oxide (rGO), featuring a unique three-dimensional nanostructure and excellent glucose electrocatalytic performance with a wide detection range of 1-800 µM. Additionally, density functional theory calculations have revealed the synergetic role of Pt active sites in the Pt single-atom catalyst (Co3O4/rGO/Pt) in glucose adsorption and electron transfer, thereby enhancing sensor performance. To enable application in wearable devices, we designed an S-shaped microfluidic chip and a point-of-care testing (POCT) device, both of which were validated for effectiveness through actual use by volunteers. This research provides valuable insights and innovative approaches for analyzing sweat glucose using wearable devices, contributing to the advancement of personalized healthcare.


Biosensing Techniques , Glucose , Graphite , Platinum , Sweat , Wearable Electronic Devices , Biosensing Techniques/instrumentation , Sweat/chemistry , Platinum/chemistry , Humans , Catalysis , Glucose/analysis , Graphite/chemistry , Electrochemical Techniques/instrumentation , Nanotubes/chemistry , Limit of Detection , Equipment Design , Oxides/chemistry
8.
Mikrochim Acta ; 191(6): 336, 2024 05 22.
Article En | MEDLINE | ID: mdl-38777836

A nanocomposite of Ce-doped ZnO/r-GO was synthesized using a conventional hydrothermal method. The synthesized nanocomposites were utilized for the purpose of sensitive and selective detection of cyclobenzaprine hydrochloride (CBP). The properties of the composite were extensively analyzed, including its morphology, structure, and electrochemical behavior. This study investigates the application of a modified glassy carbon electrode for the detection of CBP, a muscle relaxant used to treat musculoskeletal diseases that cause muscle spasms. The electrode is modified with Ce-doped ZnO/r-GO. Various detection methods, such as cyclic voltammetric and square wave techniques (SWV), were utilized. The composite material showed high effectiveness as an electron transfer mediator in the oxidation of CBP. The electrode showed a good response for SWV evaluations in CBP identification, with a minimum detection limit of 1.6 × 10-8 M and a wide linear range from 10 × 10-6 M to 0.6 × 10-7 M, under ideal conditions. The rate constant for charge transfer (ks) and the estimation of the electrochemical active surface area were obtained. A developed sensor exhibited desirable selectivity, long-lasting stability, and remarkable reproducibility. A sensor was used to analyze water, human serum, and urine samples, resulting in positive recovery results.


Amitriptyline , Electrochemical Techniques , Electrodes , Limit of Detection , Zinc Oxide , Zinc Oxide/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Amitriptyline/chemistry , Amitriptyline/urine , Amitriptyline/blood , Amitriptyline/analogs & derivatives , Nanocomposites/chemistry , Humans , Muscle Relaxants, Central/chemistry , Muscle Relaxants, Central/urine , Muscle Relaxants, Central/blood , Muscle Relaxants, Central/analysis , Reproducibility of Results
9.
ACS Sens ; 9(5): 2662-2672, 2024 May 24.
Article En | MEDLINE | ID: mdl-38689483

Dopamine (DA) signaling is critically important in striatal function, and this metabolically demanding process is fueled largely by glucose. However, DA and glucose are typically studied independently and, as such, the precise relationship between DA release and glucose availability remains unclear. Fast-scan cyclic voltammetry (FSCV) is commonly coupled with carbon-fiber microelectrodes to study DA transients. These microelectrodes can be modified with glucose oxidase (GOx) to generate microbiosensors capable of simultaneously quantifying real-time and physiologically relevant fluctuations of glucose, a nonelectrochemically active substrate, and DA, which is readily oxidized and reduced at the electrode surface. A chitosan hydrogel can be electrodeposited to entrap the oxidase enzyme on the sensor surface for stable, sensitive, and selective codetection of glucose and DA using FSCV. This strategy can also be used to entrap lactate oxidase on the carbon-fiber surface for codetection of lactate and DA. However, these custom probes are individually fabricated by hand, and performance is variable. This study characterizes the physical nature of the hydrogel and its effects on the acquired electrochemical data in the detection of glucose (2.6 mM) and DA (1 µM). The results demonstrate that the electrodeposition of the hydrogel membrane is improved using a linear potential sweep rather than a direct step to the target potential. Electrochemical impedance spectroscopy data relate information on the physical nature of the electrode/solution interface to the electrochemical performance of bare and enzyme-modified carbon-fiber microelectrodes. The electrodeposition waveform and scan rate were characterized for optimal membrane formation and performance. Finally, codetection of both DA/glucose and DA/lactate was demonstrated in intact rat striatum using probes fabricated according to the optimized protocol. Overall, this work improves the reliable fabrication of carbon-fiber microbiosensors for codetection of DA and important energetic substrates that are locally delivered to the recording site to meet metabolic demand.


Biosensing Techniques , Carbon Fiber , Dopamine , Glucose Oxidase , Glucose , Microelectrodes , Dopamine/analysis , Glucose/analysis , Carbon Fiber/chemistry , Biosensing Techniques/methods , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Animals , Carbon/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Hydrogels/chemistry , Rats , Rats, Sprague-Dawley , Brain/metabolism , Chitosan/chemistry , Mixed Function Oxygenases/chemistry , Mixed Function Oxygenases/metabolism , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism
10.
Bioelectrochemistry ; 158: 108722, 2024 Aug.
Article En | MEDLINE | ID: mdl-38697015

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis is the need of the hour, as cases are persistently increasing, and new variants are constantly emerging. The ever-changing nature of the virus leading to multiple variants, has brought an imminent need for early, accurate and rapid detection methods. Herein, we have reported the design and fabrication of Screen-Printed Electrodes (SPEs) with graphene oxide (GO) as working electrode and modified with specific antibodies for SARS-CoV-2 Receptor Binding Domain (RBD). Flexibility of design, and portable nature has made SPEs the superior choice for electrochemical analysis. The developed immunosensor can detect RBD as low as 0.83 fM with long-term storage capacity. The fabricated SPEs immunosensor was tested using a miniaturized portable device and potentiostat on 100 patient nasopharyngeal samples and corroborated with RT-PCR data, displayed 94 % sensitivity. Additionally, the in-house developed polyclonal antibodies detected RBD antigen of the mutated Omicron variant of SARS-CoV-2 successfully. We have not observed any cross-reactivity/binding of the fabricated immunosensor with MERS (cross-reactive antigen) and Influenza A H1N1 (antigen sharing common symptoms). Hence, the developed SPEs sensor may be applied for bedside point-of-care diagnosis of SARS-CoV-2 using miniaturized portable device, in clinical samples.


Biosensing Techniques , COVID-19 , Electrodes , Graphite , SARS-CoV-2 , Graphite/chemistry , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , Humans , COVID-19/diagnosis , COVID-19/virology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Immunoassay/methods , Immunoassay/instrumentation , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/analysis , Limit of Detection
11.
ACS Sens ; 9(5): 2346-2355, 2024 May 24.
Article En | MEDLINE | ID: mdl-38713172

Dopamine (DA) and serotonin (5-HT) are neurotransmitters that regulate a wide range of physiological and behavioral processes. Monitoring of both neurotransmitters with real-time analysis offers important insight into the mechanisms that shape animal behavior. However, bioelectronic tools to simultaneously monitor DA and 5-HT interactive dynamics in freely moving animals are underdeveloped. This is mainly due to the limited sensor sensitivity with miniaturized electronics. Here, we present a semi-implantable electrochemical device achieved by integrating a multi-surface-modified carbon fiber microelectrode with a miniaturized potentiostat module to detect DA and 5-HT in vivo with high sensitivity and selectivity. Specifically, carbon fiber microelectrodes were modified through electrochemical treatment and surface coatings to improve sensitivity, selectivity, and antifouling properties. A customized, lightweight potentiostat module was developed for untethered electrochemical measurements. Integrated with the microelectrode, the microsystem is compact (2.8 × 2.3 × 2.1 cm) to minimize its impacts on animal behavior and achieved simultaneous detection of DA and 5-HT with sensitivities of 48.4 and 133.0 nA/µM, respectively, within submicromolar ranges. The system was attached to the crayfish dorsal carapace, allowing electrode implantation into the heart of a crayfish to monitor DA and 5-HT dynamics, followed by drug injections. The semi-implantable biosensor system displayed a significant increase in oxidation peak currents after DA and 5-HT injections. The device successfully demonstrated the application for in vivo simultaneous monitoring of DA and 5-HT in the hemolymph (i.e., blood) of freely behaving crayfish underwater, yielding a valuable experimental tool to expand our understanding of the comodulation of DA and 5-HT.


Astacoidea , Dopamine , Electrochemical Techniques , Microelectrodes , Serotonin , Animals , Dopamine/analysis , Serotonin/analysis , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Wireless Technology , Carbon Fiber/chemistry , Biosensing Techniques/methods
12.
ACS Sens ; 9(5): 2520-2528, 2024 May 24.
Article En | MEDLINE | ID: mdl-38723023

Alternative energy sources are required due to the decline in fossil fuel resources. Therefore, devices that utilize hydrovoltaic technology and light energy have drawn widespread attention because they are emission-free and solar energy is inexhaustible. However, previous investigations mainly focused on accelerating the water evaporation rate at the electrode interface. Here, a cooperative photoelectrochemical effect on a hydrovoltaic chip is achieved using NH2-MIL-125-modified TiO2 nanotube arrays (NTs). This device demonstrated significantly improved evaporation-triggered electricity generation. Under LED illumination, the open-circuit voltage (VOC) of the NH2-MIL-125/TiO2NTs active layer of the hydrovoltaic chip was enhanced by 90.3% (up to 400.2 mV). Furthermore, the prepared hydrovoltaic chip showed good high-salinity tolerance, maintaining 74.6% of its performance even in 5 M NaCl. By introducing a Schiff-based reaction between the active layer and formaldehyde, a fully integrated flexible sensor was successfully fabricated for formaldehyde monitoring, and a low limit of detection of 5.2 × 10-9 M was achieved. This novel strategy for improving the performance of hydrovoltaic devices offers a completely new general approach to construct self-powered devices for point-of-care sensing.


Electrochemical Techniques , Formaldehyde , Titanium , Formaldehyde/analysis , Formaldehyde/chemistry , Titanium/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Nanotubes/chemistry , Salinity , Photochemical Processes , Electrodes , Limit of Detection
13.
Mikrochim Acta ; 191(6): 348, 2024 05 28.
Article En | MEDLINE | ID: mdl-38805077

A novel aptamer-based sensor was developed using the signal amplification strategy of ring-opening metathesis polymerization (ROMP) and polyethyleneimine modified graphene oxide to achieve trace detection of carbendazim (CBZ). The dual identification of aptamer and antibody was used to avoid false positive results and improve the selectivity. Polyethyleneimine modified graphene oxide (GO-PEI), as a substrate material with excellent conductivity, was modified on the surface of a glassy carbon electrode (GCE) to increase the grafting amount of aptamer on the electrode surface. Moreover, a large number of cyclopentenyl ferrocene (CFc) was aggregated to form long polymer chains through ring-opening metathesis polymerization (ROMP), so as to significantly improve the detection sensitivity of the biosensor. The linear range of this sensor was 1 pg/mL-100 ng/mL with a detection limit as low as 7.80 fg/mL. The sensor exhibited excellent reproducibility and stability, and also achieved satisfactory results in actual sample detection. The design principle of such a sensor could provide innovative ideas for sensors in the detection of other types of targets.


Aptamers, Nucleotide , Benzimidazoles , Biosensing Techniques , Carbamates , Electrochemical Techniques , Graphite , Limit of Detection , Polyethyleneimine , Polymerization , Graphite/chemistry , Carbamates/chemistry , Carbamates/analysis , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Polyethyleneimine/chemistry , Biosensing Techniques/methods , Benzimidazoles/chemistry , Aptamers, Nucleotide/chemistry , Electrodes , Reproducibility of Results
14.
Mikrochim Acta ; 191(6): 350, 2024 05 28.
Article En | MEDLINE | ID: mdl-38806865

Gold nanomaterials have been widely explored in electrochemical sensors due to their high catalytic property and good stability in multi-medium. In this paper, the reproducibility of the signal among batches of gold nanorods (AuNRs)-modified electrodes was investigated to improve the data stabilization and repeatability. Ordered and random self-assembled AuNRs-modified electrodes were used as electrochemical sensors for the simultaneous determination of dopamine (DA) and topotecan (TPC), with the aim of obtaining an improved signal stability in batches of electrodes and realizing the simultaneous determination of both substances. The morphology and structure of the assemblies were analyzed and characterized by UV-Vis spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). Electrochemical studies showed that the ordered AuNRs/ITO electrodes have excellent signal reproducibility among several individuals due to the homogeneous mass transfer in the ordered arrangement of the AuNRs. Under the optimized conditions, the simultaneous detection results of DA and TPC showed good linearity in the ranges 1.75-45 µM and 1.5-40 µM, and the detection limits of DA and TPC were 0.06 µM and 0.17 µM, respectively. The results showed that the prepared ordered AuNR/ITO electrode had high sensitivity, long-term stability, and reproducibility for the simultaneous determination of DA and TPC, and it was expected to be applicable for real sample testing.


Dopamine , Electrochemical Techniques , Electrodes , Gold , Limit of Detection , Nanotubes , Topotecan , Dopamine/analysis , Gold/chemistry , Topotecan/analysis , Topotecan/chemistry , Reproducibility of Results , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Nanotubes/chemistry , Humans
15.
J Agric Food Chem ; 72(21): 11900-11916, 2024 May 29.
Article En | MEDLINE | ID: mdl-38709250

Food quality and safety are related to the health and safety of people, and food hazards are important influencing factors affecting food safety. It is strongly necessary to develop food safety rapid detection technology to ensure food safety. As a new detection technology, artificial nanochannel-based electrochemical and other methods have the advantages of being real-time, simple, and sensitive and are widely used in the detection of food hazards. In this paper, we review artificial nanochannel sensors as a new detection technology in food safety for different types of food hazards: biological hazards (bacteria, toxins, viruses) and chemical hazards (heavy metals, organic pollutants, food additives). At the same time, we critically discuss the advantages and disadvantages of artificial nanochannel sensor detection, as well as the restrictions and solutions of detection, and finally look forward to the challenges and development prospects of food safety detection technology based on the limitations of artificial nanochannel detection. We expect to provide a theoretical basis and inspiration for the development of rapid real-time detection technology for food hazards and the production of portable detection equipment in the future.


Biosensing Techniques , Food Contamination , Food Safety , Food Contamination/analysis , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Nanostructures/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation
16.
Food Chem ; 452: 139430, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38713984

As emerging contaminants, microplastics threaten food and environmental safety. Dibutyl phthalate (DBP, released from microplastics) and benzo[a]pyrene (BaP, adsorbed on microplastics) coexisted in food and the environment, harming human health, requesting a sensitive and simultaneous testing method to monitor. To address current sensitivity, simultaneousness, and on-site portability challenges during dual targets in complex matrixes, CuCo2S4/Fe3O4 nanoflower was designed to develop a smartphone-assisted photoelectrochemical point-of-care test (PEC POCT). The carrier transfer mechanism in CuCo2S4/Fe3O4 was proven via density functional theory calculation. Under optimal conditions, the PEC POCT showed low detection limits of 0.126, and 0.132 pg/mL, wide linearity of 0.001-500, and 0.0005-50 ng/mL for DBP and BaP, respectively. The smartphone-assisted PEC POCT demonstrated satisfied recoveries (80.00%-119.63%) in real samples. Coherent results were recorded by comparing the PEC POCT to GC-MS (DBP) and HPLC (BaP). This novel method provides a practical platform for simultaneous POCT for food safety and environment monitoring.


Electrochemical Techniques , Food Contamination , Microplastics , Smartphone , Food Contamination/analysis , Microplastics/analysis , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Limit of Detection , Environmental Monitoring/instrumentation , Environmental Monitoring/methods , Copper/analysis , Copper/chemistry , Benzo(a)pyrene/analysis , Dibutyl Phthalate/analysis
17.
Food Chem ; 452: 139536, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38723569

Eating food contaminated by foodborne pathogens can lead to illness. The development of electrochemical sensors for pathogen detection has received widespread attention. However, the analytical performance of electrochemical sensors is inevitably affected by the non-specific adsorption of molecules in the sample. Moreover, the external signal probes might be affected by the complex components in the sample accompanied with signal suppression. This work presents an electrochemical aptasensor for Salmonella typhimurium detection based on the self-signal of poly-xanthurenic acid and the antifouling ability of chondroitin sulfate. The detection time was 60 min. The linear range was from 101 to 107 CFU/mL, and the detection limit was 3 CFU/mL. The biosensors presented good repeatability and storage stability. And the biosensors has been successfully applied in milk and orange juice. This strategy is expected to be applied in the design of other antifouling biosensors, to achieve rapid detection of pathogens and ensure food safety.


Biosensing Techniques , Electrochemical Techniques , Food Contamination , Milk , Salmonella typhimurium , Biosensing Techniques/instrumentation , Salmonella typhimurium/isolation & purification , Electrochemical Techniques/instrumentation , Food Contamination/analysis , Milk/microbiology , Milk/chemistry , Animals , Limit of Detection , Food Microbiology , Fruit and Vegetable Juices/analysis , Fruit and Vegetable Juices/microbiology , Citrus sinensis/microbiology , Citrus sinensis/chemistry
18.
Food Chem ; 452: 139548, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38728894

In this study, an electrochemical sensor based on MoS2 with enhanced electrochemical signals from electrochemically activated carbon cloth (EACC) electrodes and cross-linked o-aminothiophenol functionalized AuNPs (o-ATP@AuNPs) was developed for the detection of the unsaturated vegetable oil antioxidant tert-butylhydroquinone (TBHQ). In this approach, carbon cloth is activated through the implementation of electrochemical methods, thereby effectively increasing its specific surface area. The resulting EACC, serving as an electrode substrate, enables the growth of additional nanomaterials and enhances conductivity. The incorporation of MoS2 effectively augments the sensitivity of the electrochemical sensor. Subsequently, MIP/MoS2/EMCC is formed via electropolymerization, utilizing TBHQ as the template molecule and o-ATP@AuNPs as the functional monomer. The SS bond of o-ATP ensures a strong and stable connection between MoS2 and o-ATP@AuNPs, thereby facilitating the immobilization of MIP. In addition, the high conductivity possessed by o-ATP@AuNPs could effectively improve the sensitivity of the electrochemical sensor. Under the optimal conditions, MIP/MoS2/EMCC could determine TBHQ in the range of 1 × 10-3 µM to 120 µM by differential pulse voltammetry (DPV) with a detection line of 0.72 nM. The proposed MIP/MoS2/EMCC is expected to be applied in the future for the selective and sensitive detection of TBHQ in vegetable oils.


Electrochemical Techniques , Gold , Hydroquinones , Metal Nanoparticles , Hydroquinones/analysis , Hydroquinones/chemistry , Gold/chemistry , Electrochemical Techniques/instrumentation , Metal Nanoparticles/chemistry , Aniline Compounds/chemistry , Carbon/chemistry , Polymers/chemistry , Sulfhydryl Compounds/analysis , Sulfhydryl Compounds/chemistry , Limit of Detection , Electrodes
19.
Food Chem ; 452: 139537, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38728891

The chlortetracycline (CTC) residue in food poses a threat to human health. Therefore, developing sensitive, convenient and selective analytical methods for CTC detection is crucial. This study innovatively uses tin disulfide/bimetallic organic framework (SnS2/ZnCo-MOF) nanocomposites in conjunction with gold nanoparticles (AuNPs) to co-modify a glassy carbon electrode (GCE). Further, a molecularly imprinted polymer (MIP)-based electrochemical sensing platform Au-MIP/SnS2/ZnCo-MOF/Au/GCE (AZG) was fabricated for selective CTC detection. SnS2/ZnCo-MOF enhanced the stability and surface area of the AZG sensor. The presence of AuNPs facilitated electron transport between the probe and the electrode across the insulating MIP layer. The fixation of AuNPs and MIP via electropolymerization enhanced the selective recognition of this sensor and amplified its output signal. The AZG sensor demonstrated a wide linear detection range (0.1-100 µM), low detection limit (0.072 nM), and high sensitivity (0.830 µA µM-1). It has been used for detecting CTC in animal-origin food with good recovery (96.08%-104.60%).


Chlortetracycline , Electrochemical Techniques , Food Contamination , Gold , Metal Nanoparticles , Molecular Imprinting , Gold/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Metal Nanoparticles/chemistry , Food Contamination/analysis , Animals , Chlortetracycline/analysis , Metal-Organic Frameworks/chemistry , Tin Compounds/chemistry , Limit of Detection , Sulfides/chemistry , Anti-Bacterial Agents/analysis , Molecularly Imprinted Polymers/chemistry , Zinc/analysis , Zinc/chemistry
20.
Food Chem ; 452: 139575, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38735112

Dimetridazole (DMZ) is a broad-spectrum antibiotic effective against bacterial and protozoan infections in humans and poultry farms. However, excessive DMZ intake leads to harmful effects. Thus, minimizing its environmental presence is crucial for sustaining daily life. This study presents an innovative approach to construct flower-like SnS particle decorations on a nickel metal-organic framework (Ni-MOF@SnS) as an electrocatalyst for DMZ detection. The Ni-MOF@SnS/GCE sensor exhibits exceptional electrocatalytic behavior, including a significantly reduced detection limit of 1.6 nM, extensive linear ranges from 0.01 µM to 60 µM and from 60 µM to 231 µM at lower and higher DMZ concentrations, respectively. It also shows enhanced sensitivity (0.139 µA µM-1 cm-2) and remarkable selectivity for DMZ detection using differential-pulse voltammetry (DPV). Furthermore, the proposed sensor demonstrates good recovery results with actual food samples.


Electrochemical Techniques , Food Contamination , Metal-Organic Frameworks , Nickel , Nickel/chemistry , Nickel/analysis , Electrochemical Techniques/instrumentation , Metal-Organic Frameworks/chemistry , Food Contamination/analysis , Limit of Detection , Animals , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/pharmacology
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