Photoelectrochemical monitoring of 4-chlorophenol by plasmonic Au/graphitic carbon nitride composites

4-Chlorophenol (4-CP), a common important environmental contaminant, represents a public health concern due to its toxicity and broad antimicrobial properties. Despite tremendous efforts, developing 4-CP detection method with accuracy and sensitivity remains a great challenge. Herein, a facile and sensitive photoelectrochemical (PEC) sensing platform for the detection of 4-CP was fabricated using plasmonic Au/graphitic carbon nitride composites (Au/g-C3N4). The Au/g-C3N4 was synthesized via a one-step reduction of Au(III) on the protonated g-C3N4. Due to surface plasmon resonance of Au nanoparticles, the incorporation of Au nanoparticles was believed to play the decisive role in promoting the adsorption of light and subsequent photoelectric conversion efficiency of g-C3N4. As a result, the Au/g-C3N4 (10 wt%) achieved significant enhancement (similar to 3.4-fold) in the photocurrent density compared to g-C3N4 alone. In addition, the introduction of 4-CP was able to suppress electron-hole recombination, leading to sensitive PEC tracing of 4-CP level in aqueous solution. Furthermore, the limit of detection of the 4-CP PEC sensor has been significantly lowered to 0.08 mu M. The 4-CP PEC sensor revealed an acceptable anti-interference capacity with acceptable intra-assay precision and excellent stability, and provided the promising platform to detect 4-CP at low levels in environment. (C) 2016 Elsevier B.V. All rights reserved.