Evaluation of the Electrochemical Behavior of NADH in the Produced Gold Nanoelectrodes

OpenAlex İngilizce

In this study, gold nanoelectrodes were fabricated using a laser-based micropipette puller method and employed for investigating the nanoelectrochemical behavior of nicotinamide adenine dinucleotide (NADH). Gold wires embedded in borosilicate capillaries were subjected to thinning, sealing, and pulling processes, followed by polishing and thermal annealing to obtain reproducible nanoelectrode surfaces. The produced nanoelectrodes were characterized electrochemically by cyclic voltammetry (CV) using ferrocene as a redox mediator in acetonitrile containing 0.05 M tetrabutylammonium tetrafluoroborate (TBATFB). The average radius of the fabricated nanoelectrodes was calculated as 118.54±51.53 nm at a 95% confidence interval. The electrochemical oxidation behavior of NADH was examined in phosphate buffer solution (pH 7) containing KCl as supporting electrolyte using cyclic voltammetry and square wave voltammetry (SWV). Optimization studies were performed by varying frequency and amplitude parameters to obtain the best analytical response. The concentration–current relationship was investigated in the range of 1–4 mM NADH, and a linear relationship was obtained with a correlation coefficient of R²=0.9954. The nanoelectrodes exhibited stable and symmetrical voltammetric responses, while increased supporting electrolyte concentration improved steady-state electrochemical behavior. The findings demonstrate that laser-fabricated gold nanoelectrodes provide a promising platform for rapid and sensitive electrochemical investigation of NADH. Due to their nanoscale dimensions and favorable mass-transfer characteristics, the produced nanoelectrodes may have potential applications in biomolecule sensing and intracellular electrochemical measurements.