Gold Nanoparticle‐electrodeposited Electrodes Used for p‐Nitrophenol Detection in Acidic Media: Effect of Electrodeposition Parameters on Particle Density, Size Distribution, and Electrode Performance

Abstract

Abstract Para ‐nitrophenol ( p ‐NP) was detected using gold nanoparticle‐electrodeposited indium tinoxide electrodes (AuNP‐ITO) or AuNP‐electrodeposited screen printing carbon electrodes (AuNP‐SPC) in acidic media. AuNPs were formed by potential‐sweeping electrodeposition from the solution containing Na 2 SO 4 , H 2 SO 4 , and HAuCl 4 ·3H 2 O. The effect of electrodeposition parameters, such as the cycling number of potential scan, the cathodic switching potential, and the scan rate, on density and size distribution of AuNPs was studied. It was found that the particle density and the size distribution of the AuNPs had a crucial effect on the electrode activity to p ‐NP reduction. A AuNP‐electrodeposited electrode with appropriate size, narrow distribution, and high density of AuNPs shows the best activity to p ‐NP reduction. p ‐NP was detected by hydrodynamic chronoamperometry at –0.2 V and the dependence of the steady state current taken from the amperometric transient on concentration of p ‐NP was linear from 1.0 × 10 –7 M to 3.15 × 10 –4 M with a regression coefficient of 0.9995. The detection limit was 9.8 × 10 –8 M (13.7 ppb) (σ = 3).