Unmodified Electrode Research Articles

Electrochemical characterization of carboplatin at unmodified platinum electrodes and its application to drug consumption studies in ovarian cancer cells

Carboplatin is one of the most prescribed and essential medications for chemotherapy treatment of human cancers. Unfortunately, many patients relapse with carboplatin resistance, making treatment inefficient and cost-intense. The cellular mechanisms of carboplatin-resistance are poorly understood. One suggested mechanism is the inhibition of drug uptake to prevent the intracellular accumulation of the drug. Herein, we present an electroanalytical approach to monitor the consumption of carboplatin by drug-susceptible and drug-resistant ovarian cancer cells. For this purpose, carboplatin was thoroughly characterized by voltammetry and its suitability for physiological bioelectrochemical studies was assessed. Diffusion and adsorption processes of carboplatin were evaluated, its dependence on pH was investigated, and a limit of detection for carboplatin at unmodified Pt electrodes was identified, without the need of expensive and time-intense electrode modification strategies. Our results report the application of voltammetry as a rapid, inexpensive, and sensitive method to quantify drug consumption by cancer cells.

Selective voltammetric detection of dopamine using ferrocene modified carbon paste electrode

A selective sensor based on carbon paste electrode with ferrocene (Fc/CPE) has been investigated. The Fc/CPE was prepared for selective dopamine (DA) in presence of interference compounds as ascorbic acid (AA) and uric acid (UA). The Fc/CPE can well resolve the peak oxidation of DA, AA and UA. The modified electrode exhibited better electrocatalytic activity and catalytic efficiency 3.5 times higher than using the unmodified electrode. The electrochemical behaviours of DA at the surface of the modified electrode were studied by cyclic voltammetry (CV). Using differential sweep voltammetry (DPV) at the optimum condition the determination of DA was measured in the concentration range of 0.5 μत -10 μत with a detection limit of 0.2437 μM and a correlation coefficient of 0.9995. The Fc/CPE has been applied to determination of DA spike into simulated sample and showed good recovery.

Modification of Porous Carbon Material with Polymeric Cobalt Complex with a Schiff Base of Salen-Type for Electrodes of Electrochemical Supercapacitors

The effect of modification of a porous carbon material used to manufacture supercapacitors with a polymeric cobalt complex with a Salen-type Schiff base on the capacity of the material has been studied. Conjunction of multielectron redox processes in the polymer with the proposed effective modification technology makes it possible to increase the electrode capacity by 2.4 times in comparison with unmodified carbon electrodes. The specific capacity of the polymer poly-[Co(CH3OSaltmen)] at a polymer deposition density of 1.3 mg cm–2 was 170 mA h g–1.

Ultrathin Conformal oCVD PEDOT Coatings on Carbon Electrodes Enable Improved Performance of Redox Flow Batteries

AbstractSurface engineering of porous carbon electrodes is an effective strategy to enhance the power output of redox flow batteries (RFBs) and may enable new cost reduction pathways for energy storage. Here, a surface modification strategy that enhances the electrochemical performance of RFBs in iron‐based electrolytes is demonstrated. Nanometric films of poly(3,4‐ethylenedioxythiophene) (PEDOT) are grown conformally onto carbon cloth electrodes using oxidative chemical vapor deposition (oCVD) and the impact of film properties on electrode performance in model iron‐based electrolytes is investigated. Depositing oCVD PEDOT films on the electrode surface is found to reduce ohmic, kinetic, and mass transport resistances, with the highest current densities and lowest resistances observed for electrodes coated with a ≈78 nm thick film. As compared to unmodified electrodes, coated electrodes enhance the maximum obtained current density at an applied overpotential of 350 mV by 6.7× and 3.7× in iron sulfate and iron chloride, respectively. The oCVD PEDOT film described here represents an initial step toward electrode surfaces of tailored activity, selectivity, and wettability for specific RFB chemistries and, more generally, electrochemical systems with liquid‐phase reactants.

Potentiodynamic fabrication and characterization of poly(4-amino-3-hydroxynaphthalene sulfonic acid) modified glassy carbon electrode

Electropolymerization technique is an effective to control the thickness of the conducting polymer film. Poly (4-amino-3-hydroxynaphthalene sulfonic acid), as polymer of aniline derivative, synthesized potentiodynamically on surface of glassy carbon electrode, experienced catalytic property towards several electroactive alkaloids and pesticides in our previous reports. However, controversial arguments on whether the reported catalytic property is due to the deposited polymer film, activation of the surface during scanning the electrode in acidic medium, or the monomer itself have not been addressed. Thus, this paper describes properties of the polymer film modified electrode as compared to unmodified glassy carbon electrode, activated glassy carbon electrode, pretreated glassy carbon electrode, and monomer casted glassy carbon electrode. The effective surface area, film thickness, elemental composition, circuit elements including charge transfer resistance & double layer capacitance, and morphology determined using cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy- equipped with an energy dispersive spectrometer, atomic force microscopic, and x-ray photoelectron spectroscopic techniques as applicable confirmed the modification of the surface of the glassy carbon electrode with a conductive, electroactive, nano-sized (40-60 nm) polymer film that increased the effective surface area of the modified electrode (PGCE). The authors are now confident to conclude that the observed catalytic property of the polymer modified glassy carbon electrode towards the analytes in our reported works is thus solely due to the synergetic effects of properties of the deposited redox polymer film on the electrode surface.

Evaluation of Pt,Pd-Doped, NiO-Decorated, Single-Wall Carbon Nanotube-Ionic Liquid Carbon Paste Chemically Modified Electrode: An Ultrasensitive Anticancer Drug Sensor for the Determination of Daunorubicin in the Presence of Tamoxifen.

Measuring the concentration of anticancer drugs in pharmacological and biological samples is a very useful solution to investigate the effectiveness of these drugs in the chemotherapy process. A Pt,Pd-doped, NiO-decorated SWCNTs (Pt,Pd-NiO/SWCNTs) nanocomposite was synthesized using a one-pot procedure and combining chemical precipitation and ultrasonic sonochemical methods and subsequently characterized by TEM and EDS analysis methods. The analyses results showed the high purity and good distribution of elements and the ~10-nm diameter of the Pt,Pd-NiO nanoparticle decorated on the surface of the SWCNTs with a diameter of about 20–30 nm. Using a combination of Pt,Pd-NiO/SWCNTs and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (1B23DTFB) in a carbon paste (CP) matrix, Pt,Pd-NiO/SWCNTs/1B23DTFB/CP was fabricated as a highly sensitive analytical tool for the electrochemical determination of daunorubicin in the concentration range of 0.008–350 μM with a detection limit of 3.0 nM. Compared to unmodified CP electrodes, the electro-oxidation process of daunorubicin has undergone significant improvements in current (about 9.8 times increasing in current) and potential (about 110 mV) decreasing in potential). It is noteworthy that the designed sensor can well measure daunorubicin in the presence of tamoxifen (two breast anticancer drugs with a ΔE = 315 mV. According to the real sample analysis data, the Pt,Pd-NiO/SWCNTs/1B23DTFB/CP has proved to be a promising methodology for the analysis and measuring of daunorubicin and tamoxifen in real (e.g., pharmaceutical) samples.

A novel citrus pectin-modified carbon paste electrochemical sensor used for copper determination in biofuel

This paper reports the construction of a citrus pectin-modified carbon paste electrode (PEC/CPE) which was applied for electrochemical sensitive detection of copper in biofuel. Considering its low cost of production and ease of handling, this novel sensor is a suitable alternative tool for ensuring the quality control of commercial bioethanol. Pectin carboxylic groups presence in the modified electrode helped increase its current response by 32% compared to the unmodified electrode. Under optimized conditions, using differential-pulse anodic stripping voltammetry, the analytical curve presented linear range from 5.0 × 10−8 to 1.0 × 10−4 mol L−1 (R = 0.999), with detection limit of 2.5 × 10−8 mol L−1, quantification limit of 8.3 × 10−8 mol L−1 and sensibility of 0.12 A mol−1 L. The PEC/CPE was successfully applied for copper determination in bioethanol fuel sample where recoveries ≥99% were obtained. The sensor presented good selectivity, reproducibility and repeatability (RSD ≤ 3.6%), with long-term stability over three months (RSD ≤ 6.3%).

Simple and low-cost sensor based on activated biochar for the stripping voltammetric detection of caffeic acid

The development of simple and low-cost electrochemical sensors is of great interest for the detection of food, environmental and biological species. Biochar-based electrodes can be easily constructed using biomass waste providing these characteristics. Herein we developed a composite sensor based on activated biochar for the sensitive stripping detection of caffeic acid, exploring the spontaneous preconcentration of analyte on the biochar surface. Biochar was prepared by pyrolysis of castor cake waste biomass at 400 °C. The sorption properties of biochar were improved after chemical treatment by HNO3 refluxing, increasing the amount of oxygenated functional groups. The proposed sensor showed excellent results for caffeic acid preconcentration compared to unmodified electrodes. This demonstrates the versatility and feasibility of the biochar for the sensors development, which is also interesting from the economic and environmental point. Under optimized conditions the proposed sensor presented a wide linear range from 1.0 to 3000 µmol L−1, good repeatability and reproducibility for consecutive measurements, high sensitivity (11.06 μA L mmol−1) and low limit of detection (30.9 nmol L−1). The method was successfully applied for caffeic acid detection in real and spiked wine samples without sample pretreatment. Therefore, the use of a castor cake waste provides an eco-friendly and sustainable material for the development of a sensible and accurate sensor.

Electroactive biofilms on surface functionalized anodes: The anode respiring behavior of a novel electroactive bacterium, Desulfuromonas acetexigens

Surface chemistry is known to influence the formation, composition, and electroactivity of electron-conducting biofilms. However, understanding of the evolution of microbial composition during biofilm development and its impact on the electrochemical response is limited. Here we present voltammetric, microscopic and microbial community analysis of biofilms formed under fixed applied potential for modified graphite electrodes during early (90 h) and mature (340 h) growth phases. Electrodes modified to introduce hydrophilic groups (-NH2, -COOH and -OH) enhance early-stage biofilm formation compared to unmodified or electrodes modified with hydrophobic groups (-C2H5). In addition, early-stage films formed on hydrophilic electrodes are dominated by the gram-negative sulfur-reducing bacterium Desulfuromonas acetexigens while Geobacter sp. dominates on -C2H5 and unmodified electrodes. As biofilms mature, current generation becomes similar, and D. acetexigens dominates in all biofilms irrespective of surface chemistry. Electrochemistry of pure culture D. acetexigens biofilms reveal that this microbe is capable of forming electroactive biofilms producing considerable current density of > 9 A/m2 in a short period of potential-induced growth (~19 h following inoculation) using acetate as an electron donor. The inability of D. acetexigens biofilms to use H2 as a sole source electron donor for current generation shows promise for maximizing H2 recovery in single-chambered microbial electrolysis cell systems treating wastewaters.

The interaction between microbes and electrodes decorated with bio‐reduced graphene oxide— from an electrochemical point of view

AbstractBACKGROUNDThe extracellular electron transfer (EET) between microbes and electrodes modified by graphene‐based functional material has attracted increasing attention. EET is an important process through which the anode can act as the acceptor for the electrons produced via microbial respiration, and it also plays a key role in organic matter degradation and nutrient cycling in the environment.RESULTSOur results showed that the interaction between microbes and carbon felt (CF) electrodes decorated with bio‐reduced graphene oxide (GO‐br) was significantly enhanced compared to that between the unmodified CF electrode and microbes. The promoted biological current production and cyclic voltammetric (CV) current response indicated the considerable electro‐activity of the GO‐br‐CF electrode. diffusion resistance (Rdif) of the GO‐br‐CF electrode decreased significantly by 97.3% from 2.76 × 105 ± 7644 Ω at the initial incubation stage to 7341 ± 1322 Ω after 58 h of incubation time for GO‐br decoration. We also noticed that the GO‐br‐CF electrode intermittently poised at +0.1 V (vs Ag/AgCl/KCl sat.) was favorable for EET. The GO‐br‐CF electrode, which enhanced MFC performance significantly, was further used as the anode in a microbial fuel cell (MFC).CONCLUSIONOverall, the results of this study indicated the decoration of CF electrode with GO‐br could regulate the electrochemical activity of the electrode and the EET process between the microbes and electrode. The elevated electrochemical activity and EET were attributed to the rapid decrease in the diffusion resistance (Rdif) of the GO‐br‐CF electrode.

Direct Electrochemistry and Sensitive Detection of Guanosine on Nanopolymeric Surfaces Bearing Boronic Acid Groups

AbstractThis paper describes the use of novel boronic acid containing polymeric surfaces for following improved direct electrochemistry and highly sensitive and selective electrochemical detection of guanosine. Effective and robost boronic acid containing electroactive polymeric layers based on poly(3‐aminophenylboronic acid) (PAPBA) in the existence of a convenient nanomaterial (multi‐walled carbon nanotubes, MWCNTs) were fabricated onto graphite surfaces with a simple and reproducible single‐step electro‐fabrication method for the first time. So‐formed electrodes were then utilized for direct electrochemistry of guanosine and determination of guanosine. The electrode presented a linearity to guanosine from 1 μM to 120 μM and the detection limit was calculated as 0.14 μM (n=3). It was feasible to differentiate guanine and guanosine with a good peak separation value of 0.31 V. Furthermore, analytical performance of this novel electrode was compared with the performances of graphene added polymeric layer modified graphite electrode and unmodified graphite electrode.

Enhanced electro-oxidation of methanol at nanoparticle-based Ru/Pt bimetallic catalyst: Impact of GC substrate pretreatment

This study addresses the facile preparation of electro-active Ru–Pt binary nanocatalyst layer electrodeposited onto glassy carbon (GC) electrodes for efficient methanol electrooxidation reaction (MOR). Unmodified GC and GC electrodes modified with Nafion (Naf/GC) and zeolite (Naf-Zeo/GC) are used as substrates for the electrodeposition of the Ru–Pt binary catalyst. Morphological, compositional, crystallographic and electrochemical characterizations were disclosed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) unit, XRD, and cyclic voltammetry (CV), respectively. The electrocatalytic activity of the various modified GC electrodes towards MOR depends markedly on the structure of the catalyst layer and the pretreatment of the underlying GC substrate as well. The highest catalytic activity was obtained at Ru–Pt/Naf-Zeo/GC electrode as demonstrated in highest peak current and favorable negative shift of the onset potential of MOR. The underlying zeolite increases the tolerance of the Ru–Pt catalyst layer against CO poisoning possibly by facilitating its oxidative removal and thus retrieval of Pt active sites.

Electrocatalytic Oxidation Study of Theophylline on a Copper Nanoparticles-Modified, Carbon Paste Electrode Based on Cyclic Voltammetry

In this study, the Cu nanoparticles were prepared by reducing CuSO4. These particles were used in making copper nanoparticles modified carbon paste electrode (nano-CPE). The electrochemical characteristics of this electrode (nano-CPE) were investigated. The results of the electrocatalytic oxidation of theophylline (TP) on nano-CPE, using the cyclic voltammetry technique showed that nano-CPE, has more reactivity and more effective surface area, as compared to the unmodified carbon paste electrode (un-CPE). The investigation of voltammograms obtained from oxidation of TP at different scan rates on the nano-CPE confirmed a cyclic mediated redox mechanism followed by reducing Cu(III) which is a chemical reaction (EC mechanism). These species formed in more positive potentials and act as a redox intermediate for TP oxidation. There was a linear relationship between the oxidation peak current and the square root of the scan rate, showing that the oxidation reaction of TP at nano-CPE might be due to the diffusion-controlled process.

Determination of Rosmarinic acid in plant extracts using a modified sensor based on magnetic imprinted polymeric nanostructures

In this work, a modified carbon paste electrode (CPE) was designed and fabricated base on magnetic functionalized molecularly imprinted polymer (MMIP) nanostructure for selective determination of Rosmarinic acid (RA) in some plant extracts. The MMIP nanostructure functionalized with –NH2 group (Fe3O4@SiO2@NH2) was prepared by surface imprinting approach and then used as modifier for destruction of modified sensor. According to sample characterization, nano-sized functionalized MMIP particles (i.e. Fe3O4@SiO2@NH2) with super-paramagnetic behavior was confirmed. The magnetization saturation value of Fe3O4@SiO2@NH2 sample was decreased from 43 emug−1 to 9 emug−1 after MIP coating. In addition, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used for study the electrochemical behavior and determination of RA on the modified CPE. Based on the results, the modified sensor has good sensitivity and selectivity for the detection of RA in the presence of other species compared to unmodified electrodes. Under optimum conditions, two linear concentration ranges (0.1−100 μM and 100−500 μM) with a low detection limit (0.085 μM), and a good precision were obtained. Finally, applicability of the designed sensor was examined for determination of RA in four plant extracts including Salvia officinalis, Zataria multiflora, Mentha longifolia, and Rosmarinus officinalis, successfully.

Simple sonochemical synthesis of SrCuO2 assisted GCN nanocomposite for the sensitive electrochemical detection of 4-AAP

The present study demonstrates the development of an electrochemical sensor to detect and quantify 4- Aminoantipyrene (4-AAP), using strontium copper oxide (SrCuO2) microspheres and graphitic carbon nitride (GCN) as a composite in the modified graphite electrode. The SrCuO2 is synthesized by sonochemical method and GCN was prepared using pyrolysis method. Field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD) techniques are used in the characterization of the synthesized materials. Subsequently, the well characterized GCN and SrCuO2 are deposited onto a graphite (Gr) surface and used as transducer material in the fabrication of the electrode. Electrochemical characterization of the as fabricated electrode was carried out with the help of electrochemical impedance spectroscopy (EIS). The results validated the conducting nature of SrCuO2 and GCN. In Comparison with the unmodified electrode, the proposed Gr/SrCuO2/GCN electrochemical sensor, displayed enhanced electrocatalytic behavior towards 4-AAP. The sensor's analytical performance is calibrated and evaluated by cyclic voltammetry (CV) and Differential pulse voltammetry (DPV). The sensor exhibited exceptional characteristics like wide linear range, low detection limit. In addition, the proposed sensor also showed an excellent repeatability, good reproducibility and superior stability. Finally, the real sample analysis results indicated an acceptable recovery range that endeavored the use of the proposed sensor to monitor 4-AAP.

Simple two-stages synthesis of Ni/P-MWCNTs nanocomposite as efficient catalyst for the hexachlorobenzene electrochemical dechlorination

The present work describes the economical two-stages catalytic CVD method of the nanocomposite of phosphorous-doped multi-walled carbon nanotubes with nickel (Ni/P-MWCNTs) from the solution of the triphenylphosphine in ethanol using Ni/CaO catalyst. The structure of Ni/P-MWCNTs nanocomposite was studied by high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), X-ray diffraction (XRD), and nitrogen adsorption-desorption method. The Ni/P-MWCNTs nanocomposite are characterized as a mixture of the cylindrical and bamboo-like predominately closed nanotubes with an average outer diameter of 31 nm and SBET=186 m2/g. The P atoms covalently bonded to the carbon framework of the P-MWCNTs walls predominantly through the oxygen bridges. The metal was found in Ni(0) form on the P-MWCNTs tips that is only partially covered by graphene layers. The clusters of bulk Ni(NiO) was also detected in the sample. The glassy carbon electrode modified by the Ni/P-MWCNTs nanocomposite exhibit good electrocatalytic activity in the hexachlorobenzene stepwise degradation and showed an average potential shift of ∼200 mV and ∼130 mV for each stage to the less negative potentials compared to the unmodified glassy carbon electrode and glassy carbon electrode coated by undoped MWCNTs.

Electrochemical detection of the synthetic cathinone 3,4-methylenedioxypyrovalerone using carbon screen-printed electrodes: A fast, simple and sensitive screening method for forensic samples

In this work, the electrochemical detection of 3,4-methylenedioxypyrovalerone (MDPV), a synthetic cathinone used as a stimulant drug, is presented for the first time. The electrochemical behavior of MDPV was studied by cyclic voltammetry (CV) at the surface of an unmodified glassy carbon electrode and a carbon graphite screen-printed electrode (SPE-Gr), where three irreversible oxidation processes were identified. The quantification of MDPV in seized drug samples was optimized for the first oxidation process (at + 0.6 V vs Ag) in 0.1 mol L−1 Britton Robison (BR) buffer solution pH 6.0 at SPE-Gr, using adsorptive stripping differential pulse voltammetry (AdSDPV) detection. The proposed method exhibited a limit of detection (LOD) of 0.5 µmol L−1 and suitable electrochemical response stability using the same (N = 5) or different (N = 3) electrodes, both presenting a RSD lower than 1.6%. Additionally, interference studies and application to MDPV sensing in reference samples provided by United Nations Office on Drugs and Crime (UNODC) were performed, confirming the potential of the proposed sensor for application in forensic analysis as a simple, fast and cost-effective screening method for MDPV.

Electrochemical sensor based on biochar and reduced graphene oxide nanocomposite for carbendazim determination

For the first time, a nanocomposite based on biochar and reduced graphene oxide (rGO) was employed to construct a modified carbon paste electrode and applied for the determination of carbendazim (CBZ). Biochar was obtained by through pyrolysis of Eichhornia crassipes biomass, also known how “Aguapé” at 400 °C. The modified electrode with our nanocomposite proposal shows to be able to preconcentrate CBZ and presented the highest analytical response in comparison to the unmodified electrode and by the electrodes prepared with the proposed materials separately. Using differential pulse voltammetry (DPV) under optimized conditions, the sensor showed a linear dynamic response (LDR) from 30 to 900 nmol L−1, a limit of detection (LOD) of 2.3 nmol L−1 and limit of quantification (LOQ) of 7.7 nmol L−1. No significant influence of inorganic ions or organic compounds on sensor response was verified, considering the recovery evaluation data. The proposed sensor was successfully applied for the determination of CBZ in spiked whole orange juice, lettuce leaves, drinking water, and wastewater samples. Good recovery values were found using the ex-situ methodology, showing excellent analytical performance of the electrochemical sensor based on biochar and rGO nanocomposite.

Green synthesized silver nanoparticle modified carbon paste electrode for SWAS voltammetric simultaneous determination of Cd(II) and Pb(II) in Bahir Dar Textile discharged effluent

The principal objective of this research was to demonstrate the sensitivity and selectivity of carbon paste electrode modified with Ocimum Sanctum leaf extract synthesized silver nanoparticles for simultaneous determination of Cd(II) and Pb(II) in discharged textile effluent. While UV-Vis, XRD and FT-IR were used to fully characterize the green synthesized silver nanoparticles, cyclic voltammetry was used to evaluate the electrochemical behavior of the two metals at the modified electrode relative to the unmodified electrode. Square wave anodic stripping (SWAS) voltammetric current showed linear dependence on the concentration in the range 5–160 ppm with determination coefficients (R2) of 0.9976 and 0.9996 for Cd(II) and Pb(II), respectively. The method also showed extremely low detection limit (0.0891ppm for Cd(II) and 0.048 ppm for Pb(II)) making the method superior over the previously reported methods. Recovery results of 94.3 for Cd(II) and 101.0% for Pb(II) validated the applicability of the method for simultaneous determination of the two metals in a complex matrix textile effluent sample. While levels of Pb(II) and Cd(II) in the untreated sample were 117.0 and 128.3 ppm, their levels in the treated sample were 17.7 and 101.4 ppm, respectively confirming the low efficiency of the treatment plant the factory claims to have. The level of the studied metals in the discharged effluent is much higher than the permissible limit indicating extent of pollution of the water system to which the effluent is discharged.

Electrochemical Sensor under Nanostructured Materials

In order to study the electrochemical sensor of nanometer mechanism materials to realize the high sensitive detection of different chemical molecules, in this research, the preparation methods of molybdenum dioxide nanomaterials, molybdenum dioxide/metal particles (Au, Pt, Au@Pt) composites and the preparation of molybdenum dioxide nanomaterials, molybdenum dioxide /Au composite nanomaterials, molybdenum dioxide /Pt composite nanomaterials and molybdenum dioxide /Au @Pt composite nanomaterials were introduced. Then the electrochemical behavior of several modified electrodes, electrochemical behavior in catechol system, scanning and pH were applied to the modified electrode. Finally, the electrode p-catechol system was detected by differential pulse voltammetry and the actual samples were analyzed. The results showed that compared with unmodified electrode materials, the electrode modified by molybdenum dioxide nanomaterials, molybdenum dioxide /Au composite nanomaterials, molybdenum dioxide /Pt composite nanomaterials and molybdenum dioxide /Au @Pt composite nanomaterials has better electrocatalytic performance and the detection of catechol has a good effect. Among them, the electrochemical sensor constructed by MoS2-Au@Pt composite has the best detection performance for catechol. The results have a good guiding significance for the performance improvement of electrochemical sensor.