NVESTIGATION OF GOLD NANOPARTICLE MODIFICATION ON SCREEN PRINTED GOLD ELECTRODE BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY

Abstract

ecently increasing attention has been paid to the development of highly sensitive and selective electrochemical sensors for accurate and cost-effective detection in various fields. In this study, gold nanoparticles (AuNPs) were electro-deposited onto screen printed gold electrode (SPGE) surfaces at different times to determine the optimum modification conditions. Determining the optimum modification for the SPGE surface, AuNP modification under −0.3 V potential with 2 mM HAuCl4 (in 0.5 M H2SO4) solution were investigated. In this case, for the optimum AuNP modification, electrochemical impedance spectroscopy (EIS) analysis was performed at the following deposition times: 30, 60, 90, 120, and 150 s. As a result of modeling the Nyquist graph obtained in the range of 10 kHz to 0.1 Hz with the EIS analysis based on the equivalent circuit model, the outcomes for each modification time were analyzed. After the modification with AuNPs, scanning electron microscope (SEM) images of the SPGE surfaces were discussed. As a result, the optimum deposition time was determined as 90 s by the analysis. This study can be used for electrochemical investigation and target detection in complex media in terms of AuNPs on SPGE surfaces with a detailed perspective for nanoparticle deposition.