Sensitive Photoelectrochemical Determination of Ciprofloxacin Using an Indium Tin Oxide Photoelectrode Modified with Small Gold Nanoparticles
Ling Cao, Zheng Li, Rui Jia, Li Chen, Ying Wu, Junwei Di
Abstract
A highly sensitive photoelectrochemical sensor for the determination of ciprofloxacin has been fabricated using a small gold nanoparticles (AuNPs) modified indium tin oxide (ITO) electrode. It operates on the size-dependent enhancement behavior of AuNPs which efficiently increase the photocurrent intensity of the ITO/AuNPs photoelectrode due to plasmonic-excitation. The ITO/AuNPs photoelectrode self-assembled with two layers of approximately 5 nm gold nanoparticles showed the highest photocurrent response. Moreover, the adsorption of ciprofloxacin on the Au surface resulted in a decrease of photocurrent intensity at the ITO/AuNPs photoelectrode. This deceased photocurrent had a linear relationship with the ciprofloxacin concentration across a wide range from 0.1 nM to 10 µM with a low detection limit of 0.08 nM. This photoelectrochemical sensor is simple, cost-effective, highly sensitive, and very selective. This device may potential applications for the determination of ciprofloxacin in environmental waters. The proposed method was compared with other analytical methods reported in the literatures.