In situ generation of H2O2 by a layered double hydroxide as a visible light nano-photocatalyst: Application to bisphenol A quantification

Abstract

Herein, we report in situ generation of hydrogen peroxide by a nanostructured cobalt-doped zinc-aluminum layered double hydroxide (Co-doped Zn-Al LDH) under visible light irradiation. The Co-doped Zn-Al LDH photocatalyst was synthesized by a facile co-precipitation method and successfully characterized. The hydrogen peroxide was generated in situ by irradiation of the photocatalyst at λ = 525 nm. The generated hydrogen peroxide was reacted with luminol, resulted in a chemiluminescence (CL) emission at λmax = 425 nm. The CL intensity was diminished in the presence of bisphenol A (BPA). As the reduced signal was proportional to BPA concentration, an innovative CL nanosensor was introduced for BPA quantification. Several factors affecting the CL signal were studied and optimized. The CL intensity was decreased linearly with increasing BPA concentration from 0.1 to 20.0 ng mL−1. The limit of detection and relative standard deviations (%RSD, n = 5, BPA concentration: 10.0 ng mL−1) were found to be 0.03 ng Ml−1, and 4.36% and 1.9% for inter- and intra-day assays, respectively. The nano-sensor was effectively utilized for monitoring of BPA in various water samples.