Voltammetric Studies Research Articles

(Invited) Analyzing Cyclic Voltammetry to Understand (Bio)Electrocatalysis for Electrosynthesis

After meeting Diane Smith 25 years ago as a graduate student, I quickly learned the importance of careful voltammetric studies in quantitatively understanding all types of electrocatalysis. The Smith Group provided a wealth of protocols for studying all types of redox systems that have been used across the electrosynthesis field by my group and many others. This paper will discuss the use of cyclic voltammetry for studying homogeneous, heterogeneous, and biological electrocatalysis. This talk will discuss the use of fundamental electroanalysis for improving electrosynthesis.

Photocatalytic and electrochemical investigation of Mn and Sn co-doped ZnO nanoparticles: Effect of doping concentration

The chemical precipitation method is employed to prepare the Mn and Sn co-doped ZnO nanoparticles with various doping concentrations. Debye Scherrer’s formula, Williamson-Hall equation and Halder-Wagner methods are used to calculate the crystallite size of the prepared nanoparticles. The addition of dopants enhances the periodicity of the atoms. The bond lengths, second nearest neighbor distances and bond angles are examined. The purity of the samples is confirmed using energy dispersive X-ray analysis technique. The process of doping reduces the maximum optical absorption. The dopants reduce the band gap of the prepared nanoparticles and the band gap ranges from 3.07 eV to 3.03 eV. The charge carrier concentrations are calculated from the optical band gap. The Hall coefficient of the prepared nanoparticles increases due to the addition of the dopants. The refractive index of the material is also examined. The quenching is observed in the photoluminescence spectrum due to the dopants. The dielectric properties and electric modulus depend on doping concentrations of Mn and Sn. The degradation of the Congo red and methylene blue dyes with prepared nanoparticles as catalysis is reported. The specific charge of the Mn and Sn co-doped ZnO-based electrode is analyzed using cyclic voltammetric study and galvanostatic charge–discharge technique.

Electrochemical sensing of nitrate ions at Cu-immobilized gold electrode in neutral medium

The Cu-immobilized Au surface was electro-catalytically employed for nitrate ions reduction in a neutral solution. According to cyclic voltammetric studies, the Cu/Au electrode has an improved electro-catalytic impact on converting nitrate ions into nitrite ions, governed by a two-electron transfer system. This modified electrode demonstrated good performance in real sample analysis along with good sensitivity (3.2518 $ \mu A \mu M^{-1} cm^{-2}$), long linear detection range (1.2 to 111.4 $\mu M$), a very lower limit of detection (0.85 $\mu M$), an excellent reproducibility. Thus, to determine nitrate ions in an aqueous media, an electrochemical sensor based on a Cu/Au electrode is suggested. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 10(1), 2023 P 75-85

Development of a Disposable, Amperometric Glycerol Biosensor Based on a Screen-Printed Carbon Electrode, Modified with the Electrocatalyst Meldolas Blue, Coated with Glycerol Dehydrogenase and NAD+: Application to the Analysis of Wine Quality

This paper describes the design and development of a novel electrochemical biosensor for measuring glycerol in wine. Our initial detailed studies were aimed at deducing the optimum conditions for biosensor operation by conducting hydrodynamic voltammetric and amperometric studies. The resulting voltammograms revealed a maximum electrocatalytic current at 0.0 V vs. Ag/AgCl, which we used for all further studies. We also examined the effect of pH (8–10) on the amperometric responses of different glycerol concentrations over a range of 0.04 to 0.20 mM. Based on our findings, we propose that pH 9 would be suitable as the supporting electrolyte for further studies with the amperometric biosensor. The biosensor was constructed by immobilising 10 units of GLDH and 660 μg NAD+ onto the MB-SPCE surface using glutaraldehyde (GLA) as a cross-linking agent. Calibration studies were performed with glycerol over the 1.0–7.5 mM concentration range. Chronoamperometry was the electrochemical technique chosen for this purpose as it is convenient and can be performed with only 100 μL of sample directly deposited onto the biosensor’s surface. In the current study, we observed linear calibration plots with the above standard solutions using current measurements at a selection of sampling times along the chronoamperograms (30–340 s). We have evaluated the glycerol biosensor by carrying out an analysis of commercially available red wine. Overall, these findings will form a platform for the development of novel rapid technology for point-of-test evaluation of glycerol in the production and quality control of wine.

The Angiotensin Metabolite His-Leu Is a Strong Copper Chelator Forming Highly Redox Active Species.

His-Leu is a hydrolytic byproduct of angiotensin metabolism, whose concentration in the bloodstream could be at least micromolar. This encouraged us to investigate its Cu(II) binding properties and the concomitant redox reactivity. The Cu(II) binding constants were derived from isothermal titration calorimetry and potentiometry, while identities and structures of complexes were obtained from ultraviolet-visible, circular dichroism, and room-temperature electronic paramagnetic resonance spectroscopies. Four types of Cu(II)/His-Leu complexes were detected. The histamine-like complexes prevail at low pH. At neutral and mildly alkaline pH and low Cu(II):His-Leu ratios, they are superseded by diglycine-like complexes involving the deprotonated peptide nitrogen. At His-Leu:Cu(II) ratios of ≥2, bis-complexes are formed instead. Above pH 10.5, a diglycine-like complex containing the equatorially coordinated hydroxyl group predominates at all ratios tested. Cu(II)/His-Leu complexes are also strongly redox active, as demonstrated by voltammetric studies and the ascorbate oxidation assay. Finally, numeric competition simulations with human serum albumin, glycyl-histydyl-lysine, and histidine revealed that His-Leu might be a part of the low-molecular weight Cu(II) pool in blood if its abundance is >10 μM. These results yield further questions, such as the biological relevance of ternary complexes containing His-Leu.

CVD based synthesis of binder free nanostructured MgS/MoS2@NiF electrode material for asymmetric supercapacitor applications

Two-dimensional molybdenum disulfide (MoS2) electrode materials (EMs) have gained significant interest due to their remarkable electrochemical performance in renewable energy storage devices (RESDs). However, the layered agglomeration decreases the EMs practical applications in RESDs. By combining with transition metal sulfide, layered agglomeration and electrochemical performance can be improved violently. Therefore, in this research work, MoS2-based magnesium sulfide (MgS/MoS2) nanostructured EMs are synthesized on nickel foam (NiF) via a chemical-vapor-deposition (CVD) technique. The synthesis of MoS2 and heterostructured MgS/MoS2@NiF EMs having cluster of nanoparticles and nanoneedles like microstructure is confirmed by field emission scanning electron microscopic analysis. The surface area (170 m2g-1) of nanoneedles based MgS/MoS2@NiF EMs is significantly higher than the surface area (60 m2g-1) of nanoparticles based MoS2@NiF EMs, causes to increase the electrocheomical performance of the syntehsized EMs. The MgS/MoS2@NiF EMs is preserved maximum specific capacitance of 9149 Fg-1 at 10 Ag-1, energy density of 234–171 Whkg-1, power density of 2150–4300 Wkg-1 and capacitance retention of 98.2 % for 10,000 cycles. The cyclic voltammetric study is indicated that the EMs have pseudocapacitive nature (diffusion process) which is increased by addition of MgS layer over MoS2 surface. The shifting of impedance profile to y-axis confirmed the increasing diffusion rate of ions in the pores of MoS2 by the addition of MgS layer. The theoretical Dunn's model also revealed that the over-all current produced by the synthesized EMs is due to the current contribution of diffusive and capacitive controlled process. The asymmetric supercapacitor (ASC) device preserved pseudocapacitive nature with maximum specific capacitance of 701 Fg-1 at 4 Ag-1. Moreover, the ASC device is presented the energy density ranged from 288 to 151 Whkg-1, power density ranged from 3440 to 21,500 Wkg-1, Coulombic efficiency of 100 % and capacitance retention of 95 % for 10,000 cycles performed at 20 Ag-1.

Synthesis of sulphone-infused two-dimensional microporous covalent organic frameworks involving Ni(II) porphyrin and sulfur powder for the photocatalytic generation of N-benzylidene benzylamine and their derivatives

In this article, the synthesis of a two-dimensional sulfone-based microporous COF, Ni-P has been executed via C-S coupling of nickel (II) tetra(p-bromophenyl) porphyrin with sulfur powder in the presence of the catalytic amount of CuI and benzotriazole in an inert atmosphere (N2) at 120 °C for 7–8 hrs. The authenticity as well as physiochemical properties of the compound have been investigated using FT-IR, XPS, XRD, TGA, SEM, and BET. The optical band gap (1.9 eV) and electrochemical band gap (2.1 eV) of Ni-P have been calculated through UV–vis and cyclic voltammetric study which finds Ni-P a suitable candidate for photocatalytic study. In the chemical transformation reactions, Ni-P shows an excellent conversion rate of benzylamine for the generation of N-benzylidene benzylamine through oxidative coupling (yield ∼ 99 %). In the photostability study, even after 5 times, it shows good recyclability as evidenced by FT-IR and XRD data.

Novel Hybrid Copper-Based Electrode for Non-Enzymatic Electrochemical Lactic Acid Sensing in Milk Samples

A novel developed non-enzymatic electrochemical sensor was designed for the detection of lactic acid (LA) in perishable products, with a focus on monitoring milk spoilage. The sensor utilizes a hybrid copper-based electrode consisting of cuprous oxide (Cu2O), copper oxide (CuO), and copper hydroxide (Cu(OH)2), which collectively contribute to enhanced performance through their synergistic effects. Cyclic voltammetric studies revealed distinct oxidation peaks associated with LA detection, highlighting the superior catalytic effect of the Cu2O/CuO/Cu(OH)2 electrode compared to CuO alone. Further optimization of the metal loading on the electrode surface led to improve LA sensing properties. The sensor exhibited a wide linear response range (0.25–7 mM), high sensitivity (817.66 μA·mM−1·cm−2), and a low limit of detection (0.25 mM). Selectivity tests indicated negligible interference from common dairy product constituents, while stability tests showed consistent performance over a 3 week storage period (100% stability). The practical usability of the sensor was demonstrated through the quantitative analysis of LA in pasteurized milk, with recovery values ranging from 99.7% to 106.9%, confirming the feasibility of the sensor for real sample analysis. The developed multiphase copper-based electrode presents a promising platform for the sensitive and reliable detection of LA within the dairy industry.

Characterization of lead dioxide composite electrode and its electrochemical properties

TiO2 nanoparticles, as a typical inert metal oxide, were added into [Formula: see text] plating solutions to prepare Ti/PbO2+nano-TiO2 composite coatings. The effect of TiO2 nanoparticles on the electrodeposition process of PbO2 was investigated by voltammetric studies. The composition, structure and morphology of the obtained composite coatings were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. Cyclic voltammetry was employed to study the effect of nano-TiO2 particles on the PbO2 electrodeposition process. It is found that high doping (2–8 g/L) of TiO2 nanoparticles significantly decreased the crystallite size which can be attributed to a crystallite-refining effect of nano-TiO2 during the electrodeposition of PbO2.

Pre-treated glassy carbon electrode sensor for food dye erythrosine: A voltammetric study

A straightforward and extraordinarily sensitive technique for the determination of erythrosine using a pre-treated GCE sensor was presented. The electrochemical measurements were examined utilizing cyclic voltametric technique. The pre-treated sensor displayed exceptional catalytic activity towards the electrochemical oxidation of erythrosine in alkaline phosphate buffer, specifically at a pH of 11.6. The pre-treated GCE sensor facilitated the determination of erythrosine within the linear range with a detection limit of 0.8 µM and limit of quantification of about 2.8 µM respectively. A favorable recovery from samples such as jam, cake, jellies, and ice candy indicate the applicability of the proposed technique for food quality trails. The technique demonstrates remarkable reproducibility and has proven to be highly dependable for the analysis of erythrosine in food samples. The same technique can also use to administer other food colorants which are consider to be carcinogenic to the human health.

Synthesis, characterisation and voltammetric study of dimethylammonium lead iodide perovskite

In the last decade, the most investigated perovskite materials are the hybrid organic-inorganic perovskites (HOIPs) due to their optoelectronic properties and possible application in the production of photovoltaics. This interest has led to an ongoing search for new HOIP variants, alongside thorough investigations of the properties of existing HOIPs. That is why our research in the field of organic-inorganic perovskites is aimed at the synthesis, characterization, and investigation of the electrochemical properties of dimethylammonium lead iodide (DMAPbI3) using voltammetric studies. A modified synthesis of DMAPbI3, differing slightly from the one described in the literature, was performed by combining stoichiometric amounts of lead iodide (PbI2) and dimethylammonium iodide (DMAI) dissolved in acetonitrile. After conducting controlled evaporation, a yellow crystalline powder of DMAPbI3 was obtained. The identity and purity of the obtained compound were confirmed by powder X-ray diffraction (PXRD), infrared (IR) and Raman spectroscopy, and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Investigations on the electrochemical properties of DMAPbI3 by cyclic voltammetry were performed with dichloromethane (DCM) and tetrabutylammonium chloride (TBAC) as the electrolyte. A paraffin-impregnated graphite electrode (PIGE) was used as a working electrode, on which the perovskite microparticles were immobilized. The electrochemical activity of DMAPbI3 is recognized through an intense, broad, and irreversible anodic peak attributed to the oxidation of the constituents to different possible products and the decomposition of the perovskite structure.

Enhancing the energy storage performance of titanium dioxide electrode material by green doping of Nd2O3 nanoparticles for electrochemical supercapacitors

Doping of sesquioxide alloy onto TiO2 nanomaterials was carried out in a novel green chemistry method using Corallo carpus epigaeus to fabricate the electrodes for pseudocapacitors. The conducted X-ray diffraction studies demonstrated the tetragonal phase of TiO2 and hexagonal phase of Nd2O3 nanomaterials. Morphological analysis revealed the irregular shape of TiO2 materials, each exceeding 100 nm in size, while Nd2O3 materials exhibited a spherical shape within the range of 10–20 nm. Electrochemical investigations unveiled a quasi-rectangular shape in cyclic voltammetric studies and a triangular shape in galvanostatic reactions, suggesting superior electrochemical performance of the electrodes. The doped electrodes exhibited a higher specific capacitance value (785.71 F/g) compared to pure TiO2 (707.14 F/g) at a current density of 1 A/g. These findings affirm the suitability of doped electrode materials for applications in electrical energy storage.

Design and synthesis of heteroleptic Ni(II) dipyrrin complexes for electrochemical proton reduction reactions: Cyclic voltammetric and theoretical studies

The effect of nuclearity on electrochemical hydrogen generation using new heteroleptic Ni(II) complexes containing redox-active dipyrrin and dithiocarbamate ligands has been described. Complexes 1–2 have been meticulously characterized by spectroscopic studies (ESI-MS, IR, 1H, 13C NMR, UV–vis) and their structures unambiguously confirmed by X-ray single crystal analyses. Electrocatalytic properties of the complexes toward hydrogen evolution reaction have been investigated by cyclic voltammetric studies in an organic medium in the presence of acetic acid as a weak proton source. Notably, complexes 1 and 2 produce H2 via doubly reduced Ni(II) species i.e. Ni(0) in the presence of acetic acid. Further, these complexes exhibited significant electrocatalytic activity (TOF: 264 (1) and 650 s−1 (2). Controlled potential electrolysis established a minimum Faradaic efficiency of 92 (1) and 96 % (2). Complex 2 exhibited higher turnover frequency relative to 1, while 1 showed lower overpotential (0.35 V) in comparison to 2 (0.45 V). The stability of the complexes and the amount of produced H2 has been investigated by bulk electrolysis study. A tentative mechanism (ECEC; E, electrons and C, chemical steps) and involved intermediate species for the proton reduction reaction for 1 has been established by theoretical studies.

A Study on Plasminogen-Ag Nanoparticles Interaction and its Application in Sensor Development

The interaction between plasminogen and Ag nanoparticles is studied using different techniques and applied for plasminogen sensor development. Ag nanoparticles are synthesized using an algal extract and their absorbance, emission, and electrochemical oxidation signals are detected and monitored as a function of plasminogen concentration. The variation in the optical and electrochemical properties of Ag nanoparticles is correlated with the changes in the hydrodynamic size of the bioconjugate at different plasminogen concentrations. A steady decrease in the absorbance and electrochemical oxidation peak of Ag nanoparticles is observed, while a threshold plasminogen concentration results in increasing the emission of Ag nanoparticles followed by a steady decrease in signal. The decrease in the optical and electrochemical oxidation signal of Ag nanoparticles agrees with the plasminogen-induced Ag nanoparticle agglomeration shown by dynamic light scattering. Calibration curves are established based on the absorbance, emission, and voltammetric studies obtaining a limit of detection as low as 0.740 nM with a wide linear range of 0.942-18.2 nM, which is a very promising analytical system for plasminogen detection, facilitating its progress as a biomarker for different biomedical applications.

Redox behaviour of boron subphthalocyanine carbon nanotube composites

Organic redox-active carbon composites can be used as sustainable electrode materials in electrochemical energy storage systems. Among numerous redox active species, peripherally dodecafluorinated boron subphthalocyanines (F12BsubPcs) have shown electrochemical redox activities in the solution phase. Nonetheless, the electrochemical properties of solid F12BsubPcs when compositing with nano carbon warrants further investigation for potential applications in energy storage. In this work, nanometer scale axially brominated F12BsubPcs (Br-F12BsubPcs) were coated onto bare graphitized multiwalled carbon nanotubes (GCNT) and COOH-functionalized GCNT (COOH-GCNT) by a facile dip coating method to produce two composites and to compare the effects of the surface functional group interactions with Br-F12BsubPcs. While the surface chemical and morphological characterizations confirmed the presence of Br-F12BsubPc coating on both bare and COOH-GCNTs, the coverage on the latter was higher. Cyclic voltammetric studies in acidic electrolyte revealed a highly reversible redox couple on both composites with Br-F12BsubPc coated COOH-GCNT demonstrating up to c.a. 70% higher redox peak currents than with Br-F12BsubPc coated GCNT. Further analyses of the coated COOH-GCNT suggested a 2-electron transfer process. The charge transfer has fast-kinetics and a strong dependence on the proton concentration. The composites produced in this work demonstrate potential for future application in energy storage and can provide a strategy for developing BsubPc-based carbon composites.

Voltammetric study and determination of the new psychoactive substances 25H-NBOH and 25B-NBOH in synthetic urine and blotter paper samples using a composite electrode

The dramatic escalation in the quantity of new synthetic drugs in recent years has prompted the pursuit of novel methods for identifying and quantifying these substances. Notably among them are the substituted phenethylamines known as NBOHs and NBOMes. Electrochemical study and quantification of new psychoactive substances (NPS) 25H-NBOH and 25B-NBOH in synthetic urine and synthetic blotting papers are presented using differential pulse voltammetry (DPV) on a composite electrode (CE) made of graphite and polycaprolactone (PCL). Based on the cyclic voltammetry (CV) results, we propose that the drug oxidation mechanism comprises two main steps. Initially, it involves the oxidation of the secondary amine, necessitating the removal of one electron from the amino-nitrogen atom, leading to dealkylation. Subsequently, bromine or methoxy substitution takes place. Under the optimized experimental conditions for the differential pulse voltammetry (DPV) studies, analytical curves were obtained in the range of 100 to 800 ng mL−1 for 25H-NBOH and 100 to 700 ng mL−1 for 25B-NBOH (r² = 0.999), with detection limits of 19 ng mL−1 and 23 ng mL−1, respectively, and quantification limits of 64 ng mL−1 and 76 ng mL−1. The proposed method was employed for quantification of the drugs in synthetic urine and synthetic blotting papers, with recovery values between 95 % and 106 %, demonstrating no interference from the matrices.

Towards an industrial perspective for urea-to-hydrogen valorization by electro-oxidation on nickel(III): Real effluents and pilot-scale proof of concept

This paper presents an investigation into urea-to-hydrogen valorization through electro-oxidation on nickel(III). The study has dual objectives: (i) to gain a better understanding of the effects of organic compounds (other than urea) in human urine on UEO and (ii) to upscale the process to pilot-scale. Initial voltammetric studies at lab-scale using real human urine showed that urea adsorption on nickel(III) sites, followed by its electro-oxidation, competes with molecules such as creatinine, histidine, and creatine. Notably, creatinine reduced the nickel(II) oxidation signal by up to 20 %, indicating its reaction precedence over urea. Additionally, the oxidation rate of urea by nickel(III) in urine exhibited a much lower partial order (0.1), as opposed to 0.3 in KOH solution, confirming the impact of competitive adsorption. Subsequently, UEO experiments were upscaled using a specially designed 1 L undivided tubular EC reactor operating in multi-pass mode. Potentiostatic electrolysis of a urea synthetic solution was conducted over 70 h, achieving nitrogen and carbon species mass balances of over 97 %—a milestone previously unreported at this scale. The study further examined the influence of operating parameters such as anode surface area, flow rate and applied potential on the EC process. This investigation underscored the impact of factor like reactor geometry, controlled potential and temperature on process efficiency. Parameters for optimal N2 production, highest urea conversion rate, etc., were also defined. Finally, the electrolysis of human urine at pilot-scale unveiled new challenges distinct from those encountered with urea synthetic solutions.

Surface Structure to Tailor the Electrochemical Behavior of Mixed-Valence Copper Sulfides during Water Electrolysis.

The semiconducting behavior of mixed-valence copper sulfides arises from the pronounced covalency of Cu-S bonds and the exchange coupling between CuI and CuII centers. Although electrocatalytic study with digenite Cu9S5 and covellite CuS has been performed earlier, detailed redox chemistry and its interpretation through lattice structure analysis have never been realized. Herein, nanostructured Cu9S5 and CuS are prepared and used as electrode materials to study their electrochemistry. Powder X-ray diffraction (PXRD) and microscopic studies have found the exposed surface of Cu9S5 to be d(0015) and d(002) for CuS. Tetrahedral (Td) CuII, distorted octahedral (Oh) CuII, and trigonal planar (Tp) CuI sites form the d(0015) surface of Cu9S5, while the (002) surface of CuS consists of only Td CuII. The distribution of CuI and CuII sites in the lattice, predicted by PXRD, can further be validated through core-level Cu 2p X-ray photoelectron spectroscopy (XPS). The difference in the electrochemical response of Cu9S5 and CuS arises predominantly from the different copper sites present in the exposed surfaces and their redox states. In situ Raman spectra recorded during cyclic voltammetric study indicates that Cu9S5 is more electrochemically labile compared to CuS and transforms rapidly to CuO/Cu2O. Contact-angle and BET analyses imply that a high-surface-energy and macroporous Cu9S5 surface favors the electrolyte diffusion, which leads to a pronounced redox response. Post-chronoamperometric (CA) characterizations identify the potential-dependent structural transformation of Cu9S5 and CuS to CuO/Cu2O/Cu(OH)2 electroactive species. The performance of the in situ formed copper-oxides towards electrocatalytic water-splitting is superior compared to the pristine copper sulfides. In this study, the redox chemistry of the Cu9S5/CuS has been correlated to the atomic arrangements and coordination geometry of the surface exposed sites. The structure-activity correlation provides in-depth knowledge of how to interpret the electrochemistry of metal sulfides and their in situ potential-driven surface/bulk transformation pathway to evolve the active phase.

Electrochemical activation of zinc oxide decorated graphene oxide modified carbon paste electrode surface for investigation of bisphenol-A and sulfadiazine: A voltammetric study

The rapid monitoring of drugs has robust global desire for environment has high efficacy. In this study the Zinc Oxide/Graphene Oxide modified carbon paste electrode (ZnO/GO/MCPE) was used for the voltammetric determination of Bisphenol-A (BPA) and Sulfadiazine (SFZ). The characterization of synthesized ZnO NP’s done by XRD, SEM and EDX technique; the morphological character of procured graphene oxide is done by SEM and ZnO/GO/MCPE brings the tremendous sensitivity towards the detection of BPA and SFZ utilizing CV and LSV techniques. The pH, concentration and scan rate parameters investigation were performed for BPA and SFZ, the ZnO/GO/MCPE is employ for SFZ and BPA in simultaneous determination. the limit of detection was established to be 0.209 µM and 2.760 µM respectively.

From e-waste to eco-sensors: synthesis of reduced graphene oxide/ZnO from discarded batteries for a rapid electrochemical bisphenol A sensor.

Improper disposal of used dry cell batteries and the leaching of bisphenol A (BPA), a prevalent endocrine disruptor present in food packaging, into surface water pose a significant threat to both the environment and drinking water, threatening the sustainability of the ecosystem. Thus, it is imperative to manage detrimental e-waste and regularly monitor BPA using a sensitive and reliable technique. This study proposes a cost-effective reduced graphene oxide/zinc oxide (rGO/ZnO) nanohybrid, entirely synthesized from electronic waste, for electrochemically detecting BPA in an aqueous medium. Graphite and metallic Zn precursors obtained from discarded batteries were employed to synthesize rGO/ZnO. The successful characterization of the prepared rGO and rGO/ZnO nanohybrid was conducted through different state-of-the-art techniques. An rGO/ZnO-modified glassy carbon electrode (GCE) exhibited superior conductivity and a larger surface area. Voltammetric study at the rGO/ZnO-modified GCE successfully detected BPA in an aqueous medium, demonstrating a one-electron and proton pathway for BPA oxidation. The sensor demonstrated a linear response within the concentration range of 1-30 μM, with a limit of detection of 0.98 nM and sensitivity of 0.055 μA μM-1. The developed electrode could also detect BPA in real water samples with reasonable recovery. These findings imply that the developed sensor has the potential to be a sensitive, practical, and economical monitoring system for BPA in water.