μA μM Research Articles

Construction of Stable 2D Cationic Breathing Ni-MOF for Cr(VI) Trapping and Electrochemical Sensing.

Pollution of surface water by heavy metal hexavalent chromium ions poses a serious threat to human health; herein, a two-dimensional (2D) cationic breathing Ni-MOF with free nitrate ions between the layers was designed and synthesized according to the characteristics of hexavalent chromium ions, {[Ni(L)2](NO3)2·5H2O}n (L = 1,3,5-tris[4-(imidazol-1-yl)phenyl]benzene). The flexible layer spacing of the 2D breathing Ni-MOF allows the exchange of NO3- by CrO42- without destroying the original structure. Electrostatic and hydrogen bonding interactions between CrO42- and Ni-MOF facilitate its exchange with NO3-. Moreover, CrO42- exhibits a higher binding energy with Ni-MOF compared to NO3-, and the hydrophobic channels of Ni-MOF favor CrO42- trapping due to its lower hydration energy. Consequently, Ni-MOF demonstrates both effective sorption and electrochemical sensing of Cr(VI), achieving a sensitivity of 2.091 μA μM-1 and a detection limit of 0.07 μM.

Electrochemical detection of quercetin at a Pt nanoaggregate-decorated Ti3C2-modified electrode

The surface chemical state of the electrode modification material, particularly crystal defects, significantly affects electrochemical detection properties. In this study, Ti3C2 decorated by Pt nanoaggregates (Pt NAs-Ti3C2) with enhanced crystal defect was developed for quercetin detection, where Pt nanoaggregates on Ti3C2 exhibit improved dispersibility and smaller particle size, generating a more favorable environment for interfacial catalytic reactions. A large specific surface area, the Pt NAs-Ti3C2 composite is beneficial for the adsorption and transfer of quercetin on the electrode surface. In comparison to Pt nanoaggregates with complete crystals, the Pt NA-Ti3C2-modified glassy carbon electrode (Pt NA-Ti3C2/GCE) demonstrates superior quercetin detection capabilities, achieving a detection sensitivity of 72.3 μA μM−1 and an outstanding detection linear region of 0.1–1500 nM. Besides, the electrode showcases excellent reproducibility with RSD of 2.41 %, repeatability with RSD of 1.08 %, and long-term stability with 92.3 % of the original signal retained, and resistance to interference, achieving accurately and selectively quercetin detection even in the presence of other ions and compounds. In addition, the Pt NA-Ti3C2/GCE allows for precise quercetin detection in real-life samples. Our findings establish a theoretical guideline and furnish the material foundation for the development of high-performance electrochemical sensors.

Disposable glutamate biosensor based on platinum nanoparticles, carbon quantum dots and poly-L-aspartic acid

This study reports the design and development of a disposable amperometric biosensor for the determination of L-glutamate. Glutamate oxidase (GlOx) was immobilized onto a screen-printed carbon electrode (SPE) modified with poly-L-Aspartic acid (PAsp), carbon quantum dots (CQD), and platinum nanoparticles (PtNP) for the construction of the biosensor. The surface composition of the modified SPE was optimized using the one variable at a time method. The morphological properties of the biosensor were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The electrochemical behavior of the modified electrodes was studied by cyclic voltammetry. Under the optimized experimental conditions the linear working range, detection limit and sensitivity of the GlOx/PtNP/CQD/PAsp/SPE were found to be 1.0 − 140 µM, 0.3 µM and 0.002 µA µM−1, respectively. The GlOx/PtNP/CQD/PAsp/SPE biosensor also exhibited good measurement repeatability. The as-developed biosensor was applied for the determination of L-glutamate in spiked serum samples and the average analytical recovery of added glutamate was 98.9 ± 3.9%.

A high-performance wearable microneedle sensor based on a carboxylated carbon nanotube-carbon nanotube composite electrode for the simultaneous detection of uric acid and dopamine

Uric acid (UA) and dopamine (DA) are crucial biomarkers in the human body. However, there is limited research on detecting UA or DA in subcutaneous interstitial fluid (SISF), and no studies on their simultaneous detection in SISF. Here, we developed an electrochemical microneedle sensor based on the carboxylated carbon nanotubes/multiwalled carbon nanotubes (CCNT/CNT) composite electrode for the simultaneous detection of UA and DA. Highly carboxylated CCNT was prepared and mixed with CNT and organosilicon-modified acrylic resin to form the CCNT/CNT composite. The carboxyl functional groups of CCNT enhance the electrode’s adsorption of UA and DA, while CNT improves electron conduction. The sensor achieves a wide linear detection range for UA (5–600 μM) with high sensitivity (7.13 μA μM−1 cm−2) and linearity (R2 = 0.994), as well as a wide linear range for DA (2–200 μM) with high sensitivity (13.31 μA μM−1 cm−2) and linearity (R2 = 0.994). The sensor achieved simultaneous detection of DA and UA in artificial interstitial fluid (ISF), with sensitivity and linearity remaining nearly unchanged compared to that in PBS, and is not affected by high levels of ascorbic acid (AA). Finally, the sensor successfully detected changes in UA levels in ISF of subjects before and after alcohol consumption in vivo, demonstrating its practical application capabilities. This study presents a practical strategy for detecting human biomarkers characterized by low cost, easy fabrication and excellent performance of electrode materials, and a well-designed microneedle sensor preparation scheme, making it highly promising for further research extension.

Catalysis of oxygen reduction reaction by iron porphyrin and its sensing application

Hemin, or iron porphyrin, serves as a non-noble metal catalyst for the oxygen reduction reaction (ORR). The stability of hemin is maintained in high salt concentrations, functioning as an ORR redox catalyst in the aqueous phase. Hemin facilitates the development of an oxygen sensor that transitions the ORR mechanism from a 2-electron to a more efficient 4-electron process. This sensor demonstrates excellent reproducibility (RSD<5%), with a wide linear range of 38.9–613 μM, a sensitivity of 0.136 ± 0.003 μA μM−1, and a limit of detection (3SB/m) of 11.8 μM.

Dual Sensing of Dopamine and Acetaminophen Mediated by Biomass Derived Phosphorous Rich Carbon

AbstractMultimolecular detection using a single electrode matrix as well as utilization of inexpensive non‐metal doped carbon from biomass is an attractive approach to developing low‐cost sensors. Herein, we report the synthesis of phosphorous‐doped carbon (PDC) from almond seed skin by a simple self‐polymerization method and utilized as a sensing matrix for Dopamine (DA) and Acetaminophen (APAP) whose redox potential is nearer. The phytic acid in the almond seed skin provides phosphorus to the carbon during high‐temperature treatment. The elemental analysis results confirm the existence of phosphorous in PDC. The sensing results illustrate that the PDC modified glassy carbon electrode (PDC/GCE) exhibits excellent performance against DA and APAP with a wide linear range (0.5 μM–10 μM). The detection limit (LOD) and sensitivity have been calculated and the value is found to be 0.130 μM, 0.047 μA μM−1 for DA and 0.335 μM, 0.021 μA μM−1 for APAP, respectively. The sensitivity of PDC/GCE in real sample conditions was measured using DA and APAP spiked human serum and plasma samples, the results indicate excellent recoveries ranging from 96.00 % to 103.10 %. These encouraging findings reveal that the PDC is an appropriate material for determining the DA and APAP.

Construction of Cu2Y2O5/g-C3N4 Novel Composite for the Sensitive and Selective Trace-Level Electrochemical Detection of Sulfamethazine in Food and Water Samples.

The most frequently used sulfonamide is sulfamethazine (SMZ) because it is often found in foods made from livestock, which is hazardous for individuals. Here, we have developed an easy, quick, selective, and sensitive analytical technique to efficiently detect SMZ. Recently, transition metal oxides have attracted many researchers for their excellent performance as a promising sensor for SMZ analysis because of their superior redox activity, electrocatalytic activity, electroactive sites, and electron transfer properties. Further, Cu-based oxides have a resilient electrical conductivity; however, to boost it to an extreme extent, a composite including two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets needs to be constructed and ready as a composite (denoted as g-C3N4/Cu2Y2O5). Moreover, several techniques, including X-ray diffraction analysis, scanning electron microscopy analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy were employed to analyze the composites. The electrochemical measurements have revealed that the constructed g-C3N4/Cu2Y2O5 composites exhibit great electrochemical activity. Nevertheless, the sensor achieved outstanding repeatability and reproducibility alongside a low limit of detection (LOD) of 0.23 µM, a long linear range of 2 to 276 µM, and an electrode sensitivity of 8.86 µA µM-1 cm-2. Finally, the proposed GCE/g-C3N4/Cu2Y2O5 electrode proved highly effective for detection of SMZ in food samples, with acceptable recoveries. The GCE/g-C3N4/Cu2Y2O5 electrode has been successfully applied to SMZ detection in food and water samples.

Molecularly Imprinted Polypyrrole-Modified Screen-Printed Electrode for Dopamine Determination.

This paper introduces a quantitative method for dopamine determination. The method is based on a molecularly imprinted polypyrrole (e-MIP)-modified screen-printed electrode, with differential pulse voltammetry (DPV) as the chosen measurement technique. The dopamine molecules are efficiently entrapped in the polymeric film, creating recognition cavities. A comparison with bare and non-imprinted polypyrrole-modified electrodes clearly demonstrates the superior sensitivity, selectivity, and reproducibility of the e-MIP-based one; indeed, a sensitivity of 0.078 µA µM-1, a detection limit (LOD) of 0.8 µM, a linear range between 0.8 and 45 µM and a dynamic range of up to 350 µM are achieved. The method was successfully tested on fortified synthetic and human urine samples to underline its applicability as a screening method for biomedical tests.

Fabrication of dual-functional smart materials: 2D-WO3/rGO nanocomposite for electrochemical detection and photocatalytic degradation of tetracycline

The extensive utilization of the antibacterial agent tetracycline (TC) in pharmaceuticals and livestock farming has sparked considerable health apprehensions for the welfare of both animals and humans. The presence of TC drug residues in soil, rivers, lakes, and groundwater further exacerbates these concerns. To address these issues, we synthesized WO3/rGO nanocomposites using a simple hydrothermal method and explored their bifunctional catalyst properties for the first time. These nanocomposites were investigated for their potential applications in electrochemical sensing and photocatalytic degradation of TC drug. The electrocatalytic oxidation of TC drug using the WO3/rGO/Glassy Carbon Electrode (GCE) nanocomposites demonstrated good sensitivity, low detection limit, low quantification limit and wide linear range of 1.708 µA µM−1 cm−2, 202 nM, 0.202 µM and 0.1–400 µM, respectively. Moreover, we assessed the WO3/rGO/GCE nanocomposites effectiveness in detecting TC drug in real samples, including milk, lake water, fish, and tap water, and found the recovery results to be satisfactory. Additionally, the nanocomposites displayed noteworthy photocatalytic activity in degrading the TC drug. The as-prepared WO3/rGO nanocomposites exhibited an impressive degradation efficiency of 87.5 % over 120 minutes under UV–visible light irradiation. Radical trapping tests confirmed that the *OH- radicals played a significant role in the degradation process. Our study highlights the outstanding electrochemical and photocatalytic properties of WO3/rGO nanocomposites, positioning them as highly promising materials for future biomedical and environmental applications.

Mechanochemically synthesized flower-like bismuth oxyhalides: An electrochemical platform for diclofenac detection

The emerging drug diclofenac (DICF) has been found to penetrates aquatic systems at alarming concentrations and poses serious and irreversible ecotoxicological threats around the world. In this work, we present the solid-state mechanochemical synthesis of 3D flower-like bismuth oxyhalides (BiOX, where X = Cl, Br, and I) as electrode materials for electrochemical detection of DICF. The characteristics of the flower-like BiOX are systematically investigated using spectroscopic and microscopic techniques. The BiOI-modified glassy carbon electrode (GCE) exhibits superior electrochemical performance for DICF detection compared to the pristine GCE, BiOCl/GCE, and BiOBr/GCE. The 3D flower-like architecture of BiOI facilitates favorable electrocatalytic activities due to its abundant electroactive sites, good conductivity, large surface area, and fast ion diffusion. Notably, the BiOI/GCE displays wide linear ranges (0.5–11.3 & 11.3−76), a low limit of detection (0.11 μM), high sensitivity (1.33 μA μM–1 cm–2), excellent repeatability (2.91 %), good reproducibility (2.88 %), and anti-interfering ability (<±5 %). To validate the practicality of the fabricated BiOI/GCE, the quantitative detection of DICF in human urine and river water is demonstrated and achieves acceptable recovery values. This study introduces an innovative approach to design and produce electrode materials with distinct properties, enabling enhanced electrocatalysis for various electrochemical sensing applications.

Fabrication of Nanobioengineered Interfaces Utilizing Quaternary Nanocomposite for Highly Efficient and Selective Electrochemical Biosensing of Urea.

Nanobioengineered interfaces have gained attention owing to their small size and high surface area-to-volume ratio for utilization as a platform for highly selective and sensitive biosensing applications owing to the integration of biological molecules with engineered nanomaterials/nanocomposites. In this work, a novel Ag-complex, [(PPh3)2Ag(SCOf)]-based quaternary Ag-S-Zn-O nanocomposites (NCs), was synthesized through an environmentally-friendly process. The results revealed the formation of the NCs with an average crystallite size and particle size of 36.08 and 40.22 nm, respectively. In addition, this is the first study to utilize such NCs synthesized via a single-source precursor method, offering enhanced sensor performance due to their unique structural properties. Further, these NCs were used to fabricate a urease (Ur)/Ag-S-Zn-O NCs/ITO nanobioengineered electrode for precise and sensitive electrochemical biosensing of urea. The interfacial kinetic studies revealed quasi-reversible processes with high electron transfer rates and linear current responses, indicating efficient reaction dynamics. A high diffusion coefficient and low surface concentration suggested a fast diffusion-controlled process, affirming the electrode's potential for rapid and sensitive urea detection. The biosensor demonstrated notable sensing properties such as high sensitivity (12.56 μA mM-1 cm-2) and a low detection limit (0.54 mM). The fabricated bioelectrode was highly selective and reproducible and demonstrated stability for up to 60 days. These results validate the potential of this nanobioengineered interface for next-generation biosensing applications, paving the way for advanced point-of-care diagnostics and real-time health monitoring.

Bentonite clay/carbon matrix-based voltammetric sensor for the detection of valganciclovir

In the present investigation, an electrochemical sensor based on bentonite clay (BNC) was designed and exploited for pharmaceutical applications. Valganciclovir (VLGC) is a member of the aromatic compounds known as purines and L-valyl esters, and it is employed for treating cytomegalovirus retinitis. The overdosage leads to some adverse effects on human health; it is also found as a contaminant in the environmental samples. This demands the analytical tool to track the trace level of VLGC in clinical and environmental samples. The developed sensor (BNC/CPE) was employed in the electrochemical detection of the antiviral drug Valganciclovir (VLGC) using CV and SWV techniques. The developed sensor was employed to evaluate the physiochemical constituents of the electrochemical process by investigating the effect of scan rates on the irreversible signals of VLGC. BNC/CPE sensor shows the detection limits of 13.5 nM for VLGC with a good sensitivity of 35.22 µA µM−1 cm−2. The developed sensor was employed to detect the desired drug moiety in the urine samples, pharmaceutical drugs, spiked water, and soil samples. The good recoveries (93.64–102.11 %) demonstrating the applicability and selectivity of the sensor were supported by excipient interference investigation. Thus, the developed sensors and methods make them as a promise for future research to determine other bio-active molecules in pharmaceutical and clinical samples.

Intelligent machine learning enabled sensor for acyclovir using NiMnO3 flower-like electrocatalyst

Hierarchical flower-like NiMnO3 was prepared using a hydrothermal route for oxidative detection of acyclovir (ACV), an antiviral pharmaceutical pollutant. The flower-like structure with an electroactive surface area (EASA) of 0.0952 cm2 enables non-revisable oxidation of ACV, with differential pulse voltammetry (DPV) and amperometry confirming its robust analytical capability in both high (15–75 µM) and low (0.1–1.0 µM) concentration ranges, respectively. Using amperometry, the sensor achieved an estimated limit of detection (LOD) of 1.59 nM (S/N=3) with selective oxidation of ACV and a sensitivity of 1.039µA µM−1 cm2 in the presence of other common interferants. The adaptation of machine learning (ML) algorithms like random forest, XGBoost, linear regression, and ANN validated sensors’ performance and confirmed ANN’s superiority in DPV signal interpretation. NiMnO3, as an electrocatalyst for ACV oxidation, validated by ANN modeling, highlights bimetallic oxides’ potential as a cost-effective, versatile platform for detecting pharmaceutical pollutants.

Ruthenium-based microstructures modified by gold particles as composite electrode material for non-enzymatic epinephrine detection

A simple and efficient technique for voltammetric enzymeless detection of epinephrine (EP) was proposed. In this technique, we applied hierarchical Ru-based electrode modified by Au nano- to micro-sized particles that was fabricated using laser-assisted synthesis. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to characterize electrochemical properties of the fabricated electrode material. For EP detection, we obtained two DPV calibration curves that were linear in the range of 0.05–5 μM and 5–500 μM. The highest sensitivity (45.0 μA μM−1 cm−2) and the lowest detection limit (6.4 nM) were observed for the first linear range, whereas the estimated sensitivity and limit of detection for the second linear range were 2.0 μA μM−1 cm−2 and 18.7 nM, respectively. We also demonstrated that the proposed technique can be used for selective EP determination in the presence of such common interfering analytes as ascorbic acid and dopamine. The results of this study can be potentially used for development of low-cost voltammetric sensor platforms for non-enzymatic epinephrine detection.

Facile synthesis and fabrication of Mg2SnO4/carbon black as a sustainable electrode for determination of non-steroidal anti-inflammatory drug-flutamide

The accumulation of hazardous pharmaceutical wastes in aquatic organisms, particularly nonsteroidal anti-inflammatory drug molecules, has severe toxicological consequences for both aquatic life and humans. To protect the environment, it is essential to develop a highly efficient device with dual-purpose capabilities for drug detection while minimizing catalyst expenditure. In this work, we explored a simple and effective design for fabricating a magnesium stannate combined with carbon black (Mg2SnO4/CB) nanocomposite as a cost-effective, sustainable electrode material for the electrochemical detection of flutamide (Flu). The Mg2SnO4/CB nanocomposite was synthesized through a simple hydrothermal process followed by sonication. Various analytical methods were used to determine its physico-chemical characteristics. The electrochemical efficiency of Mg2SnO4/CB/GCE was evaluated by detecting Flu, showing a remarkable linear range from 0.6 to 198.4 µM with a sensitivity of 4 μA μM−1 cm−2. In addition, the constructed sensor demonstrated excellent selectivity, high repeatability, outstanding reproducibility, and long-lasting stability. The anti-interference experiments yielded a definite current response without any change in peak shifts. Consequently, Mg2SnO4/CB/GCE demonstrated superior performance in determining Flu in human urine and river water samples.

Organic conjugated polymer nanoparticles enhanced tyrosinase electrochemical biosensor for selective, sensitive and rapid detection of bisphenol A

Bisphenol A (BPA) has been widely used in the production of polycarbonate (PC) plastics, flame retardants and epoxy resins, which is one of the most important endocrine disrupting chemicals and can cause damage to the estrogen system of human. In this work, organic conjugated polymer nanoparticles (CPNPs) were synthesized through nanoprecipitation method using liposome 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000] (DSPE-mPEG2000) coated poly[(4,4′-bis(2-ethylhexyl)-dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-4,7-di(4-hexyl-2-thienyl)-5,6-difluoro-2,1,3-benzothiadiazole] (PDTS-hDTBT) and poly[(4,4′-bis(2-ethylhexyl)-dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-4,7-di(4-(2-ethylhexyl)-2-thienyl)-5,6-difluoro-2,1,3-benzothiadiazole] (PDTS-ehDTBT). These two polymers have different side chains, which can affect the configuration of the polymers, thereby affecting the π-π interaction between BPA and CPNPs. The resultant two CPNPs were explored as extremely attractive matrix for tyrosinase immobilization to construct electrochemical biosensing platforms for sensitive and rapid detection of BPA in water environments. The electrochemical performance of these two biosensors was significantly enhanced, benefiting from the large specific surface area and excellent biocompatibility of CPNPs, as well as the strong π-π interaction between CPNPs and BPA. The current response of PDTS-ehDTBT-Tyr-Chi/GCE exhibited a good linear relationship with BPA concentration ranging from 0.02 to 3.0 μM with a low detection limit of 11.83 nM and a high sensitivity of 0.9724 μA μM−1 cm−2. The fabricated biosensor was further used for BPA detection in actual samples with a recovery rate of 92.0 %–99.4 %. With the remarkable advantages, CPNPs-based biosensor provides a highly sensitive detection tool for rapid detection of BPA in actual samples, which has broad application prospects.

Electrochemical Determination of Carbofuran Residues using WS2 Modified Electrodes

AbstractTo meet the increasing demands for food production, the utilization of cost‐effective pesticides like carbofuran (CB) becomes essential. CB poses a significant risk to human health due to its high toxicity. Therefore, accurate quantification of CB residue is essential for environmental safety and human health. Electrochemical sensors have proven to be an outstanding choice for the accurate detection and quantification of carbofuran residues. CB is electrochemically inactive and was first hydrolyzed in an alkaline medium to yield an anodically active phenolic derivative carbofuran phenol (CP). This report details the development of a voltammetric sensor for the accurate detection of CB residues utilizing the cyclic voltammetry technique and the electrochemical reactions of CP at WS2 nanosheet‐modified electrodes in phosphate buffer solution (PBS). The constructed sensor has displayed a linear range of carbofuran detection from 10–90 μM, with a limit of detection (LOD) of 0.38 μM and sensitivity of 0.303 μA μM−1 cm−2. Additionally, the developed sensor has been employed to monitor CB residues in real soil and water samples and it shows a recovery greater than 95 %. The developed sensor enables the cost‐effective monitoring of carbofuran in real samples.

Facile construction of binary metal oxide heterojunction with hexagonal boron nitride nanohybrid electrocatalyst for the detection of flutamide

BackgroundFlutamide (FU) is a potential anti-androgen drug significantly prescribed to all human beings. The high solubility and poor degradability of its metabolites can adversely affect the balance of the ecosystem. Therefore, developing an efficient and reliable technique to detect this pollutant is essential. Consequently, electrochemical sensors have been widely used for the monitoring of various real-world samples. MethodsHence, nickel-zinc oxide (NZO) with hexagonal boron nitride (h-BN) nanocomposite was prepared as a proficient electrocatalyst in FU detection. Several spectroscopic measurements were carried out to characterize the prepared materials. Our NZO/h-BN nanocomposite was utilized to modify the glassy carbon electrode (GCE) and its relative catalytic activity was scrutinized with impedance and various voltammetric techniques. Significant findingsBased on the results, our NZO/h-BN/GCE sensor exhibited high conductance, appreciable linear ranges, low detection limit (0.002 μM), optimal sensitivity (2.149 µA µM−1 cm−2), and high selectivity with good repeatability, and reproducibility results. Furthermore, the practical utility of the sensor was studied by monitoring FU in human and environmental samples. Based on the outcomes, our NZO/h-BN/GCE is a promising electrochemical platform for the detection of FU.

Facile fabrication of bismuth oxide anchored graphene oxide for the effective electrochemical sensing of diuron

BackgroundDiuron (DU), a weed controller widely used in the agricultural industry, prolonged conception of this agrochemical residue contaminated with environmental water bodies and soil sources could cause an acute impact on the human health system. This work utilized the electrochemical determination technique due to their rapid detection, outstanding sensitivity, and economical purpose. MethodsThe electrochemical behavior of DU at the γ-Bi2O3 microplates interconnected with sheet-like graphene oxide (GO) as a surface-modified electrode was scrutinized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The surface-modified γ-Bi2O3/GO/GCE elucidates superior electrocatalytic performance towards the irreversible oxidation response of diuron than the other surface-modified electrode in the phosphate buffer solution of 0.1 M. Significant findingsThe γ-Bi2O3/GO/GCE electrode displayed an extensive detection range of 0.1–631 µM with a 0.751 µM lower detection limit furthermore, noticeable 0.0280 µA µM-1 cm-2 sensitivity for diuron determination. In addition, the DPV experiment exposed that the γ-Bi2O3/GO/GCE electrode achieves stupendous selectivity, durability, and acceptable feasibility of the real-time samples.

Gold nanoparticle decorated bismuth vanadate casting on screen-printed electrode for chlortetracycline detection

Chlortetracycline is one of the tetracyclines with broad-spectrum antibacterial activity (CTC). Humans rarely use CTC, but farm animals consume vast quantities of it, which causes the growth of antibiotic-resistant bacteria and environmental contamination. There is no report on the AuNPs and BiVO4 nanocomposite being dropped cast on SPCE for electrochemical monitoring of the CTC, and the most expensive, time-consuming, and expensively equipped method is conventional chromatography. Here, we report a simple method for preparing gold nanoparticle decorated bismuth vanadate (AuNPs@BiVO4), which was dropped cast on a screen-printed carbon electrode (SPCE). The AuNPs@BiVO4 and AuNPs@BiVO4/SPCE materials were characterized using TEM, SEM-EDX, XPS, DLS, ELS, EIS, and CV, showing a consistent nanocomposite and its electrode. The as-prepared AuNPs@BiVO4/SPCE was used to detect and determine chlortetracycline (CTC) by different pulse potentials in phosphate buffer pH 7.0. The electrode possessed a wide linear range of 0.99–19.06 µM, with obtained LOD = 0.15 µM, LOQ = 0.49 µM, and sensitivity = 0.059 μA μM−1 cm−2. It also exhibited good selectivity, stability, and repeatability, recovering 87.14 %–100 % for detecting CTC in Mili Q and tap water. The findings show that the straightforward approach for making AuNPs@BiVO4 nanocomposite and an AuNPs@BiVO4/SPCE electrode is consistent with electrochemical CTC monitoring. Thus, the proposed electrode could be applied for the detection and determination of CTC in water sources and has the potential to be used for real sample analysis.