Electrochemical Sensor For Sensitive Detection Research Articles

An Electrochemical Sensor Based on 3D Graphene‐Cyclodextrin Nanohybrid for Enhanced Sensitivity Detection of Nitroaromatic Compounds

This study presents an electrochemical sensor for sensitive detection of nitroaromatic compounds using a three‐dimensional (3D) porous graphene with polyoxypropylene supported reduced graphene oxide (PEA‐RGO) and embedded β‐cyclodextrins (β‐CD). First, PEA‐RGO was synthesized by the condensation reaction between graphene oxide (GO) and amino‐terminated polyoxypropylene (PEA), followed by hydrazine hydrate reduction. Then, β‐CD was embedded into the porous of the above 3D graphene to obtain PEA‐RGO/β‐CD nanohybrid. Various characterization techniques, such as microscopy imaging, infrared spectrometry, thermal analysis and electrochemical measurements, were employed to confirm the successful synthesis and unique 3D architecture structure of PEA‐RGO/β‐CD. Afterwards

A novel bacillus-shaped CoNi ZIF-MXene@MWCNT carbon cloth electrochemical sensor for sensitive detection of salidroside

A meticulously engineered bacillus-shaped CoNi ZIF-MXene@MWCNT carbon cloth (CC) composite was synthesized through a one-step immersion method, which was employed in the development of a novel electrochemical (EC) sensor for the sensitive detection of salidroside (SAL) in Rhodiola. Characterization of the CoNi ZIF-MXene@MWCNT CC was conducted using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and EC methods. The bacillus-shaped composite showcased an exceptionally high rate of active site exposure, superior conductivity, and electrocatalytic efficiency, attributed to the synergistic effects of the constituent materials. The remarkable electrocatalytic capability facilitated the redox reaction of SAL, marked by a significant enhancement in the current signal. This led to a concentration-dependent response enabling the quantitative detection of SAL. The mechanism of the redox reaction might be the oxidation of the phenolic hydroxyl group of SAL. Demonstrating high sensitivity, selectivity, and stability, this novel bacillus-shaped composite-based EC sensor achieved a low detection limit (LOD) of 0.0958 µ g/mL for SAL, within an effective linear range of 0.5–500 µg/mL. Importantly, the EC sensor proved to be adept at practical detection of SAL in Rhodiola samples with complex matrices, and the salidroside content of Rhodiola crenulata was much higher than that of Rhodiola rosea, indicating that Rhodiola crenulata may have a higher medicinal value, offering a promising avenue for rapid and sensitive detection of SAL.

A novel electrochemical sensor for sensitive detection of carbendazim based on zeolitic-imidazolate-framework-67/carbon nanohorns nanocomposite

Herein, the zeolitic-imidazolate-framework-67/carbon nanohorns (ZIF-67/CNHs) nanocomposite was synthesized by an efficient method under mild conditions, which was applied for carbendazim (CBZ) detection. ZIF-67 with adsorption capacity of CBZ was employed as the support of proposed sensor. CNHs with excellent conductivity and large specific surface area (SSA) not only compensated the poor conductivity of ZIF-67 but also improved the SSA. The functional groups of ZIF-67 and CNHs could form hydrogen bonding, thereby reducing the aggregation of CNHs. The synergistic effect of CNHs and ZIF-67 significantly enhanced the conductivity and SSA of ZIF-67, reduced the aggregation of CNHs, and thus improved its catalytic ability towards CBZ. Based on superior characteristics of the ZIF-67/CNHs nanocomposite, the proposed sensor exhibited a low limit of detection (LOD) of 1 ng mL-1 with wide linear range of 3–3000 ng mL-1. Moreover, the proposed sensor demonstrated good selectivity, superior reproducibility, and satisfactory applicability in real samples analysis.

One-step growth of Cu-doped carbon dots in amino-modified carbon nanotube-modified electrodes for sensitive electrochemical detection of BPA.

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 0.2M PBS (pH 7.0) under optimally selected conditions. The linear range of the sensor for BPA detection was 0.5-160μM, and the detection limit (S/N = 3) was 0.13μM. 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.

Electrochemical sensor for sensitive detection of an anticancer drug Capecitabine by modified carbon paste electrode with tetrahydrodipyrazolo pyridine derivative and Cu-MCM-41 nanoparticles

In this work, the electrochemical performance of the modified carbon paste electrode with tetrahydrodipyrazolo pyridine derivative as an organic modifier, and Cu-MCM-41 nanoparticles have been investigated to determine Capecitabine (CAP), an anticancer drug. CAP has been used for treating some cancers such as rectal, stomach, breast, pancreatic, and colon cancer. It works by inhibiting cancer cells growth. Herein, an organic modifier was prepared using a green biocatalyst in a biomimetic synthesis, a simple method was used for synthesis of Cu-MCM-41 nanoparticles. The electrochemical parameters such as the transfer coefficient and the number of electrons and protons involved in the redox reaction of the modifier were calculated using cyclic voltammetry (CV). Also, an electrocatalytic reaction was observed for CAP oxidation on the modified electrode surface as a result of a reduction in the CAP species oxidation overvoltage. To measure the CAP species by the modified electrode, some optimizations were performed. The Tafel curve was used to determine the transfer coefficient between the CAP and modifier, which was determined as 0.9. The chronoamperometric experiment was also investigated to obtain the numerical value of the CAP diffusion coefficient (D = 7.67 × 10–6 cm2 s−1). The calibration curve was drawn by the differential pulse voltammetry technique (DPV), and linear ranges of 2.0–80.0 µM and 80.0–800.0 µM, and the detection limit (LOD = 0.144 µM) were obtained. To evaluate the efficiency of the proposed sensor for CAP determination, measurement was done on a real blood serum sample. The proposed sensor displayed good selectivity, repeatability, and stability.

A zinc-air battery assisted self-powered electrochemical sensor for sensitive detection of microcystin-RR.

Building a high-performance sensing platform is the key to developing sensitive sensors. Herein, a highly sensitive self-powered electrochemical sensor (SPES) was constructed using a WO3·H2O film as the cathode prepared by a hydrothermal method and Zn as the anode, and it could be applied to sensitive detection of microcystin (MC-RR). The WO3·H2O film with a larger specific surface area could boost the oxygen reduction reaction (ORR), which could achieve signal amplification and significantly increase the sensitivity of the sensors. Under the optimal conditions, there was a good linear relationship between the increased electrical power density and the logarithm of MC-RR concentration with a detection limit of 1.31 × 10-15 M (S/N = 3). This method had good anti-interference ability and stability when applied to the determination of MC-RR content in actual samples, which could boost the potential application of electrochemical sensors in the field of environmental monitoring.

Nitrogen Defect-Rich Graphitic Carbon Nitride for Highly Sensitive Voltammetric Determination of Tryptophan.

Here, a highly sensitive electrochemical sensor for detection of tryptophan (Trp) using a nitrogen defect graphitic carbon nitride-modified glassy carbon electrode (ND-CN/GCE) was introduced. ND-CN/GCE showed a higher oxidation current for Trp than the graphitic carbon nitride-modified glassy carbon electrode (g-CN/GCE) and bare glassy carbon electrode (BGCE). The synthesized nitrogen defect-rich graphitic carbon nitride (ND-CN) was characterized using X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical impedance spectroscopy and cyclic voltammetry were used to further analyze the electrochemical properties of BGCE, g-CN/GCE, and ND-CN/GCE. The oxidation of Trp at ND-CN/GCE is a diffusion-controlled process at pH 3.0. It was calculated that the transfer coefficient, rate constant, and diffusion coefficient of Trp were 0.53, 2.24 × 103 M-1 s-1, and 8.3 × 10-3 cm2 s-1, respectively, at ND-CN/GCE. Trp was detected using square wave voltammetry, which had a linear range from 0.01 to 40 μM at pH 3.0 and a limit of detection of about 0.0034 μM (3σ/m). Analyzing the presence of Trp in a milk and multivitamin tablet sample with a percentage recovery in the range of 97.0-108% satisfactorily demonstrated the practical usability of the electrochemical sensor. The ND-CN/GCE additionally displays good repeatability and reproducibility and satisfactory selectivity.

Zeolitic imidazolate framework-8/polyaniline nanocomposite-based electrochemical sensor for sensitive detection of imidaclothiz

Imidaclothiz (IMZ) is a class of neonicotinoid insecticide which can pose potential threat to human health and be frequently detected in water and foods. Herein, a zeolitic imidazolate framework-8/polyaniline (ZIF-8/PANI) nanocomposite has been modified on the surface of glassy carbon electrode (GCE) for the electrochemical determination of IMZ, and the electrochemical detection performance of the modified electrode was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). With the large surface area of ZIF-8 and great electric conductivity of PANI, the ZIF-8/PANI-modified electrode showed a high catalytic performance towards IMZ reduction in PBS. Under the optimized conditions, the linear range was from 1.0 × 10−7 to 1.0 × 10−5 mol/L and the limit of detection was as low as 2.5 × 10−8 mol/L (S/N = 3). In addition, the developed sensor displayed high reproducibility, excellent stability, and applicability in real vegetable sample analysis, indicating that the proposed method offered an alternative approach for IMZ residues analysis.Graphical abstract

Nitrite determination in food using electrochemical sensor based on self-assembled MWCNTs/AuNPs/poly-melamine nanocomposite

A nanocomposite of multi-walled carbon nanotubes/gold nanoparticles/poly-melamine (MWCNTs/AuNPs/PM) was designed using layer-by-layer self-assembled method on glassy carbon electrode (GCE) by electrochemical deposition to construct an electrochemical sensor for sensitive detection of nitrite. First, a layer of MWCNTs was modified on electrode, and then gold nanoparticles and melamine were in-situ polymerized onto MWCNTs through self-assembled technique to form GCE/MWCNTs/AuNPs/PM. MWCNTs have large specific surface area, which increased the number of gold nanoparticles deposited on MWCNTs. Meanwhile, the doping of gold nanoparticles also improved the polymerization of melamine. The synergistic interaction of nanocomposite further improved the catalytic effect on nitrite. Under optimized conditions, the detection range for nitrite was from 0.4 to 1475 μM and the detection limit was 0.041 μM. Through the detection of nitrite in food samples, the recovery rates were from 93.16% to 108.68%. Therefore, the method can be used as a practical platform for nitrite detection in food.

Electrospinning carbon fibers based molecularly imprinted polymer self-supporting electrochemical sensor for sensitive detection of glycoprotein

For glycoprotein detection that is both specific and sensitive in clinical diagnosis and treatment, it is necessary to develop artificial bionic recognition materials. By integrating boronate affinity controllable oriented surface imprinting with carbon nanofibers (CNF) as self-supported electrodes, a simple and cost-effective method for preparing glycoprotein-imprinted self-supported electrochemical biosensors was presented in this paper. The molecular imprinted polymers (MIPs) electrode based on Co, Mo2C-CNF was prepared in the presence of horseradish peroxidase (HRP) as a model glycoprotein by cyclic voltammetry. The CNF mats, composed of Co and Mo2C nanoparticles encapsulated in carbon nanofibers (Co, Mo2C-CNF) via electrospinning, could offer more electrical conductivity and active sites for the detection process. The results demonstrated that the hybrid structure of Co, Mo2C-CNF and MIPs exhibited high specificity and excellent selective recognition efficiency for HRP. The detection limit was obtained as 7.4 fg mL−1. The developed biosensor was applied to detect HRP in human serum with a recovery ranging from 89.21 % to 116.68 %. The developed MIPs electrochemical sensor has great potential for developing highly sensitive and specific glycoprotein imprinting biosensors.

Development of a novel green catalyzed nanostructured Cu(II) macrocyclic complex-based disposable electrochemical sensor for sensitive detection of bisphenol A in environmental samples

BPA is an endocrine disruptor and the leading environmental pollutant due to its use as raw material in industries. Therefore, the present work reports the sensitive, efficient, and disposable electrochemical paper-based SPE for determining the BPA sensor using an amide-based macrocyclic complex (nanostructured complex of copper acetate with macrocyclic ligand, i.e., CuL (CH3COO)2) synthesized using Citrus limon (lemon) extract via sonication for the first time. The structural, morphological, and electrochemical analyses have been characterized by mass spectroscopy, FTIR, UV–Vis, XRD, FESEM-EDX, elemental mapping and electrochemical techniques. The sensor platform for detecting BPA was fabricated by simple drop-casting on the disposable paper-based SPE using macrocyclic complex, i.e., CuL (CH3COO)2/SPE. After optimizing the conditions, CuL (CH3COO)2/SPE electrode was employed for determining BPA via CV with a wide linear range of 31 × 10−9 μM–0.205 μM, low LOD of 0.027 nM, and high sensitivity of 49.71 μA (log nM)−1 cm−2 having correlation coefficient (R2) of 0.976 which is quite better in compared to other reported SPE sensor for detection of BPA. Further, our sensor also showed good selectivity and reproducibility, in addition to detecting BPA in environmental samples (tube well water, river water and drain water) with acceptable recoveries and RSDs values. In this work, the combination of macrocyclic complex and paper-based SPE has turned out to be a cost-effective electrochemical sensor.

Electrochemical sensor for sensitive detection of bisphenol A based on molecularly imprinted TiO2 with oxygen vacancy

Bisphenol A (BPA) is an endocrine disrupting chemical and broadly used in plastics. The leakage of BPA in food and water cycles poses a significant risk to the environment and human health. Thus, monitoring the concentration of BPA to avoid its potential risk is highly important. In this work, a simple and efficient oxygen deficient molecularly imprinted TiO2 electrochemical sensor was proposed for the detection of BPA. The introduction both oxygen vacancies and molecular imprinting evidently enhanced the electrochemical oxidation signal of BPA. The sensor had a good linear response ranging from 0.01 μM to 20 μM with a limit of detection of 3.6 nM. Additionally, the sensor showed remarkable stability, reproducibility and interference resistant ability. It also exhibits excellent recovery during the detection of real water. These findings suggested that the sensor has the potential to be developed as a simple, efficient and low-cost monitoring system for the monitoring of BPA in water.

Copper oxide nanocomposite particles supported on sodium alginate-g-polyallylamine based reduced graphene oxide: An efficient electrochemical sensor for sensitive detection of cadmium ions in water

A highly sensitive and selective electrochemical sensor, sodium alginate-g-polyallylamine/reducedgrapheneoxide/CuO nanocomposite particles (SAGPMRGO@CuO NPs) has been synthesized for the detection of Cd2+ ions in the aqueous environment. The graft copolymer/reduced graphene oxide supported CuO nanocomposite particles are prepared through bioreduction of graphene oxide by a novel synthesized graft copolymer sodium alginate-g-PAAM (SAG-g-PAAM) to reduced graphene oxide (SAGPMRGO) followed by using it as both a reductant and a stabilizing agent to obtain SAGPMRGO@CuO hybrid nanocomposite particles. The graft copolymer is prepared via free radical solution phase graft copolymerization technique. The graphene oxide (GO) is prepared by the oxidation of graphite using modified Hummer's method. The prepared nanocomposite particles are characterized by UV-VIS, FTIR and Raman spectroscopy, powder X-ray diffraction (PXRD), HRTEM-EDS, FESEM, XPS and DLS analysis with zeta potential measurement in colloidal suspension. The prepared graft copolymer is characterized by 1H and 13C NMR spectroscopy, PXRD and FESEM analysis and the SAMPGRGO is characterized by UV-VIS and Raman spectroscopy, PXRD and FESEM analysis. The CuO nanocomposite particles are spindle shaped with an average particle size ranges from 15.6 nm to 32.1 nm and are well polydispersed. Metal ion (Cd2+) sensing is carried out by cyclic voltammetry (CV) and chronoamperometry (CA) analysis under optimum conditions. The limit of detection (LOD) and limit of quantitation (LOQ) is found to be 1.27 nM and 4.24 nM respectively which is lower than some other reported works. The reproducibility and stability properties of the developed sensor are examined where the results are found to be satisfactory. The selective detection of Cd2+ ions in a river water sample is also evaluated with an excellent performance.

Synergistic effect of gold nanoparticles anchored on conductive carbon black as an efficient electrochemical sensor for sensitive detection of anti-COVID-19 drug Favipiravir in absence and presence of co-administered drug Paracetamol

Favipiravir (FVP) is introduced as a promising newly developed antiviral drug against the coronavirus disease 2019 (COVID-19). Therefore, the accurate determination of FVP is of great significance for quality assessment and clinical diagnosis. Herein, a novel electrochemical sensing platform for FVP based on gold nanoparticles anchored conductive carbon black (Au@CCB) modified graphite nanopowder flakes paste electrode (GNFPE) was constructed. Morphological and nanostructure properties of Au@CCB have been investigated by TEM, HRTEM, and EDX methods. The morphology and electrochemical properties of Au@CCB/GNFPE were characterized by SEM, cyclic voltammetry (CV), and EIS. The Au@CCB nanostructured modified GNFPE exhibited strong electro-catalytic ability towards the oxidation of FVP. The performance of the fabricated Au@CCB/GNFPE was examined by monitoring FVP concentrations in the absence and presence of co-administered drug paracetamol (PCT) by AdS-SWV. It was demonstrated that the proposed sensor exhibited superior sensitivity, stability, and anti-interference capability for the detection of FVP. The simultaneous determination of a binary mixture containing FVP and the co-administered drug PCT using Au@CCB/GNFPE sensor is reported for the first time. Under optimized conditions, the developed sensor exhibited sensitive voltammetric responses to FVP and PCT with low detection limits of 7.5 nM and 4.3 nM, respectively. The sensing electrode was successfully used to determine FVP and PCT simultaneously in spiked human plasma and pharmaceutical preparations, and the findings were satisfactory. Finally, the fabricated sensor exhibited high sensitivity for simultaneous detection of FVP and PCT in the presence of ascorbic acid in a real sample.

In-situ formation of niobium oxide – Niobium carbide – Reduced graphene oxide ternary nanocomposite as an electrochemical sensor for sensitive detection of anticancer drug methotrexate

Engineering the nanostructure of an electrocatalyst is crucial in developing a high-performance electrochemical sensor. This work exhibits the hydrothermal followed by annealing synthesis of niobium oxide/niobium carbide/reduced graphene oxide (NbO/NbC/rGO) ternary nanocomposite. The oval-shaped NbO/NbC nanoparticles cover the surface of rGO evenly, and the rGO nanosheets are interlinked to produce a micro-flower-like architecture. The NbO/NbC/rGO nanocomposite-modified electrode is presented here for the first time for the rapid and sensitive electrochemical detection of the anticancer drug methotrexate (MTX). Down-sized NbO/NbC nanoparticles and rGO's high surface area provide many active sites with a rapid electron transfer rate, making them ideal for MTX detection. In comparison to previously reported MTX sensors, the developed drug sensor exhibits a lower oxidation potential and a higher peak current responsiveness. The constructed sensors worked analytically well under optimal conditions, as shown by a low detection limit of 1.6 nM, a broad linear range of 0.1–850 µM, and significant recovery findings (∼98 %, (n = 3)) in real samples analysis. Thus, NbO/NbC/rGO nanocomposite material for high-performance electrochemical applications seems promising.

A sensitive electrochemical sensor for detection of methyltestosterone as a doping agent in sports by CeO2/CNTs nanocomposite

A sensitive electrochemical sensor for detection of methyltestosterone as a doping agent in sports by CeO2/CNTs nanocomposite

Electrochemical stripping voltammetrical sensor based on polypyrrole exfoliated polyetheramine-montmorillonite nanocomposite for nanomolar detection of nifuroxazide.

A series of polypyrrole/polyetheramine-montmorillonite nanocomposites have been fabricated by the intercalation of different types of polyoxyalkylene amine hydrochloride (Jeffamines: D400, D2000, T5000, and T403) into montmorillonite layers via the cation-exchange process followed by in situ polymerization of pyrrole. The physicochemical characteristics of as-prepared nanocomposites were investigated using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and electrochemical impedance spectroscopy (EIS) instruments. The change of the types of Jeffamine causes a change in the geometrical structure, and surface area of nanocomposites. Noteworthy, the resulting polypyrrole/D2000-montmorillonite ([PDM-50]) nanocomposite exhibited a cauliflower-like shape with a specific surface area (116.2 m2 g-1) with the highest conductivity. Furthermore, the modified stripping voltammetric carbon paste sensor was fabricated based on 1.0% [PDM-50] nanocomposites to detect the drug nifuroxazide (NF). The sensor achieved detection limits (LD) of 0.24, and 0.9 nM of NF in the medication, and human urine fluid, respectively. This sensor showed appropriate repeatability, reproducibility, stability, and selectivity for NF sensing in different fluids accompanied by other interferents.

Ag-doped-CuO nanoparticles supported polyaniline (PANI) based novel electrochemical sensor for sensitive detection of paraoxon-ethyl in three real samples

In this paper, a novel nanocomposite is chemically synthesized by reinforcing Ag-doped CuO (Ag@CuO) nanoparticles into the matrix of polyaniline (PANI). This nanocomposite is used as a sensing platform for paraoxon-ethyl (PE) detection. The homogeneous distribution of Ag@CuO nanoparticles onto the PANI matrix provides a smooth and dense surface area, further accelerating the transmission of electrons. The synergistic effect of Ag@CuO and PANI matrix is responsible for the outstanding conductivity, biocompatibility, and catalytic power of the proposed biosensor. For the biosensor fabrication, the nanocomposite is electrophoretically deposited onto the surface of the ITO glass substrate and then the acetylcholinesterase (AChE) enzyme is immobilized onto the fabricated electrode surface by using glutaraldehyde as a crosslinking agent. Under all optimized detection conditions, the proposed biosensor (AChE/Ag@CuO/PANI/ITO) shows a broad linear range from 5 to 100 pM with a low detection limit (LOD) of 11.35 pM. All the electrochemical results confirm the high sensitivity (0.5536 μA (pM)−1 cm−2), high selectivity, good reproducibility, and acceptable stability of the proposed biosensor. Moreover, the proposed biosensor is successfully applied for paraoxon-ethyl (PE) detection in three real samples.

Curcumin-enhanced MOF electrochemical sensor for sensitive detection of methyl parathion in vegetables and fruits

As a typical organophosphorus pesticide, the widespread abuse of methyl parathion (MP) has seriously threatened the environment and human health. To realize the sensitive detection of MP, an electrochemical sensor based on Metal-Organic Framework UiO-66(Zr) loaded curcumin(CCM) was designed. UiO-66 with high porosity for adsorption property and CCM with unique electrochemical activity conspired to improve the sensitivity of the electrochemical sensor. The result indicated that the CCM/UiO-66 electrode was well fabricated and exhibited an enhanced electrochemical response to MP. Under optimal conditions, the CCM/UiO-66 electrode extended a wide linear range from 20 ng mL−1 to 20000 ng mL−1 and a low limit of detection of 0.98 ng mL−1. The fabricated electrode also showed excellent reproducibility and stability. Additionally, the electrode demonstrated outstanding sensing capabilities in the electrochemical detection of MP in vegetables and fruits samples.

Nitrogen-doped graphene oxide/carbon nanotubes nanocomposite (N-doped GO/CNTs) as a sensitive electrochemical sensor for detection of oxymetholone in blood serum

Nitrogen-doped graphene oxide/carbon nanotubes nanocomposite (N-doped GO/CNTs) as a sensitive electrochemical sensor for detection of oxymetholone in blood serum