Electrochemically Exfoliated WS2 Nanosheets for the Electrochemical Impedimetric Detection of NADH

• Published in: ChemElectroChem Vol. 8; no. 23; pp. 4597 - 4604
• Main Authors: Doonyapisut, Dulyawat, Kannan, Padmanathan Karthick, Kim, Byeongkyu, Chung, Chan‐Hwa
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.12.2021
• Subjects: Calibration; electrochemical exfoliation; Electrochemical impedance spectroscopy; Exfoliation; impedance spectroscopy; NADH sensor; Nanosheets; Nanostructure; Nicotinamide adenine dinucleotide; screen printed electrode; Selectivity; tungsten disulfide
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.202101343

In this work, exfoliated WS2 nanosheets were synthesized using a two‐electrode‐configured electrochemical exfoliation method and they were used as a potential material for the detection of NADH. Using screen‐printed carbon electrodes (SPCEs) as a sensing platform, exfoliated WS2 nanostructures (ex‐WS2) were drop‐casted and their electrocatalytic activity was studied in the presence of NADH. The electrochemical impedance spectroscopy (EIS) was applied as a sensing tool to achieve superior sensing performance towards NADH. At the optimized DC bias value of 0.4 V, the developed NADH sensor shows linear calibration plots in the ranges of 2 to 2048 μM. From the calibration data, the sensitivity value was found to be 36.875 Ω log([NADH])−1 with the limit of detection (LOD) value of 57 nM. In addition to that, it also exhibited very high selectivity in the presence of other possible interfering species, suggesting that the present exfoliated WS2‐modified SPCE‐based sensing platform could be used for the impedimetric label‐free monitoring of NADH in various fields. NADH sensor: The electrochemical exfoliation method is adapted for the synthesis of high‐quality WS2 nanosheets and their electrocatalytic activity towards NADH oxidation is studied using electrochemical impedance spectroscopy (EIS). The developed electrode exhibits high sensing performance in a wide NADH concentrations range of 2–2048 μM. Also, the EIS strategy helps to study the sensing mechanism at the electrode/electrolyte interface.