Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone

An efficient biosensor using a functionalized microneedle of Cu2O-based CoCu-LDH for glucose detection

Glucose detection with small and micro volume sampling has recently received increasing attention in monitoring personal health. Herein, a cauliflower-type cluster of Cu2O nanoparticles (NPs) was directly deposited on the tip surface of a stainless steel acupuncture needle electrode (ANE) by electrochemical deposition, and then this pre-formed cuprous basis was used to further prepare the neatly arranged CoCu-layered double hydroxide (CoCu-LDH) nanosheets that interconnected to form nano-sized pores in the range from 100 to 500 nm. The microstructure and spectral characteristics of the surface modification materials were comprehensively characterized by FE-SEM, EDS, XRD, FT-IR and TEM. Cu2O-based CoCu-LDH composites with special morphology had been proven to accelerate the rate of electron transport and provide more available active centers, and moreover, the mixed valence of Cu/Co induced an excellent synergism for the electrocatalytic oxidation of glucose. As a result, CoCu-LDH/Cu2O/ANE as a sensitive glucose probe exhibited two wider linear ranges of 0.03-0.40 mM and 0.40-6.00 mM, with sensitivities of 116.13 μA mM-1 and 52.08 μA mM-1, respectively, and the detection limit as low as 0.46 μM (S/N = 3). The response time only took 3 s and it kept working stably in the interference of ascorbic acid (AA), dopamine (DA), uric acid (UA), and Cl-. In the stability test, the CoCu-LDH/Cu2O/ANE sensor exhibited a stable monitoring sensitivity after 15 days. Finally, the CoCu-LDH/Cu2O/ANE sensor had been successfully applied to glucose analysis in human serum, proving that our design was an attractive strategy for developing a portable, minimally invasive, and low-cost non-enzymatic electrochemical glucose sensing platform.

A Paper-Based Electrochemical Sensor Based on PtNP/COFTFPB-DHzDS@rGO for Sensitive Detection of Furazolidone

Herein, a paper-based electrochemical sensor based on PtNP/COF_TFPB-DHzDS@rGO was developed for the sensitive detection of furazolidone. A cluster-like covalent organic framework (COF_TFPB-DHzDS) was successfully grown on the surface of amino-functional reduced graphene oxide (rGO-NH₂) to avoid serious self-aggregation, which was further loaded with platinum nanoparticles (PtNPs) with high catalytic activity as nanozyme to obtain PtNP/COF_TFPB-DHzDS@rGO nanocomposites. The morphology of PtNP/COF_TFPB-DHzDS@rGO nanocomposites was characterized, and the results showed that the smooth rGO surface became extremely rough after the modification of COF_TFPB-DHzDS. Meanwhile, ultra-small PtNPs with sizes of around 1 nm were precisely anchored on COF_TFPB-DHzDS to maintain their excellent catalytic activity. The conventional electrodes were used to detect furazolidone and showed a detection limit as low as 5 nM and a linear range from 15 nM to 110 μM. In contrast, the detection limit for the paper-based electrode was 0.23 μM, and the linear range was 0.69-110 μM. The results showed that the paper-based electrode can be used to detect furazolidone. This sensor is a potential candidate for the detection of furazolidone residue in human serum and fish samples.

Construction of Electrochemical Sensors for Antibiotic Detection Based on Carbon Nanocomposites

Excessive antibiotic residues in food can cause detrimental effects on human health. The establishment of rapid, sensitive, selective, and reliable methods for the detection of antibiotics is highly in demand. With the inherent advantages of high sensitivity, rapid analysis time, and facile miniaturization, the electrochemical sensors have great potential in the detection of antibiotics. The electrochemical platforms comprising carbon nanomaterials (CNMs) have been proposed to detect antibiotic residues. Notably, with the introduction of functional CNMs, the performance of electrochemical sensors can be bolstered. This review first presents the significance of functional CNMs in the detection of antibiotics. Subsequently, we provide an overview of the applications for detection by enhancing the electrochemical behaviour of the antibiotic, as well as a brief overview of the application of recognition elements to detect antibiotics. Finally, the trend and the current challenges of electrochemical sensors based on CNMs in the detection of antibiotics is outlined.

Immunosensor of Nitrofuran Antibiotics and Their Metabolites in Animal-Derived Foods: A Review

Nitrofuran antibiotics have been widely used in the prevention and treatment of animal diseases due to the bactericidal effect. However, the residual and accumulation of their metabolites in vivo can pose serious health hazards to both humans and animals. Although their usage in feeding and process of food-derived animals have been banned in many countries, their metabolic residues are still frequently detected in materials and products of animal-derived food. Many sensitive and effective detection methods have been developed to deal with the problem. In this work, we summarized various immunological methods for the detection of four nitrofuran metabolites based on different types of detection principles and signal molecules. Furthermore, the development trend of detection technology in animal-derived food is prospected.

A competitive-type electrochemical immunosensor based on Ce-MOF@Au and MB-Au@Pt core-shell for nitrofuran metabolites residues detection

A novel competitive-type electrochemical immunosensor based on square wave voltammetry (SWV) response was developed for the quantitative detection of 1-Aminohydantoin (AHD). To improve the conductivity of this immunosensor nanocomposites with good electrical conductivity were prepared as a signal amplification platform for the immunosensor by growing Au nanoparticles on the surface of Ce-based metal-organic framework (Ce-MOF). In addition, methylene blue (MB)-loaded Au@Pt and coating antigen (OVA-AHD) connected as a signal label. When the target was introduced, it competed with the coating antigen for the Ab, which led to a reduction in the number of signal probes bound to the Ab. The concentration of AHD can be determined by SWV detection of the MB signal loaded on the signal labels. Under optimal conditions, the wide linear range of 0.001-1000 μg /L and a low detection limit of 1.35 × 10^-7 μg/L were achieved. Ultimately, the developed method displayed excellent specificity in practical applications, providing a promising probability to detect nitrofuran metabolites residues to guarantee food safety.

Graphene oxide–porphyrin composite nanostructure included electrochemical sensor for catechol detection

A novel composite nanostructure (GO–Por) has been prepared via ultrasonication and exhibited enhanced electrocatalytic activity towards catechol oxidation.

Facile synthesis of Co(ii)-doped cobalt oxide nanostructures: their application in the sensitive determination of the prophylactic drug furazolidone

Electrochemical detection of prophylactic drug furazolidone through Co–Co₂O₄ modified GCE.

A new electrochemical sensor for the detection of fentanyl lethal drug by a screen-printed carbon electrode modified with the open-ended channels of Zn(ii)-MOF

An electrochemical fentanyl sensor based on modified screen-printed carbon electrode by Zn(ii)-MOF.

Klonopin assay using modified electrode with multiwalled carbon nanotubes and poly melamine nanocomposite

Developing of cheap, sensitive and stable sensors plays a significant role in pharmaceutical and clinical applications. Considering the effective role of Klonopin (KNP) in the treatment of epilepsy, KNP quantification in its production process for dose adjustments and checking the purity and also after its usage by patents for bioavailability testing and effectiveness assay is vital. In present work, an efficient electrochemical sensor based on poly melamine and multiwalled carbon nanotubes nanocomposite (PMela/CNTs) was constructed which displayed effective electrochemical response toward KNP. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and square-wave voltammetry (SWV) experiments were applied for performance evaluation of the PMela/CNTs modified electrode and electrochemical redox behavior of KNP. Distinguish synergetic effect was observed between CNTs and poly melamine in response to KNP electrochemical redox reaction. A linear detection range of 0.05 to 10 μM with the detection limits of 63 nM was achieved for KNP analysis. The practical application of the PMela/CNTs modified electrode revealed satisfactory results for quantification of KNP in biological fluids.

Development of an electrochemical sensor based on a functionalized carbon black/tungsten carbide hybrid composite for the detection of furazolidone

In this study, the simple sonochemical synthesis of functionalized carbon black (f-CB) anchored with tungsten carbide (WC) is used to prepare a novel electrocatalyst for the electrochemical detection of furazolidone (FU) by modifying screen-printed carbon electrodes (SPCE).

Sonochemical synthesis of molybdenum oxide (MoO3) microspheres anchored graphitic carbon nitride (g-C3N4) ultrathin sheets for enhanced electrochemical sensing of Furazolidone

Present strategy introduce the sonochemical synthesis of molybdenum oxide (MoO₃) microspheres anchored graphitic carbon nitride (g-C₃N₄) ultrathin sheets as a novel electrocatalyst for the detection of Furazolidone (FU). TEM results revealed that MoO₃ are microspheres with an average size of 2 µM and the g-C₃N₄ seems like ultrathin sheets. Owing to their peculiar morphological structure, g-C₃N₄/MoO₃ composite modified electrode provided an enriched electroactive surface area (0.3788 cm²) and higher heterogeneous electron transfer kinetics (K°_eff = 4.91×10^-2 cm s^-1) than the other controlled electrodes. It is obviously observed from the voltammetric studies that the proposed sensor based on g-C₃N₄/MoO₃ composite can significantly improve the electrocatalytic efficiency towards the sensing of FU. Due to the excellent synergic effect of g-C₃N₄/MoO₃ composite, can detect the ultra-level FU with a limit of detection of 1.4 nM and a broad dynamic range of 0.01-228 µM, which surpassed the many previously reported FU sensors. Hence, the proposed sensor was successfully applied to sensing the FU in human blood serum, urine and pharmaceutical samples, gained an agreeable recoveries.