A Highly Sensitive and Selective Electrochemical Sensor for Pentachlorophenol Based on Reduced Graphite Oxide-Silver Nanocomposites

Pentachlorophenol (PCP), commonly used as a wood preservative, pesticide, and fungicide, is the most toxic of all chlorophenols and can accumulate in living organisms. It is of great significance to construct a sensitive method for the detection of PCP in real samples. In this study, a simple, novel, and sensitive electrochemical sensor for pentachlorophenol (PCP) was constructed by modifying glassy carbon electrode (GCE) with silver-reduced graphene oxide (AgNPs-rGO) nanocomposites. Due to the increased surface area, the extraordinary electron-transfer properties, and a stronger enrichment effect of AgNPs-rGO for PCP, the sensor based on AgNPs-rGO-modified glassy carbon electrode exhibited excellent electrocatalytic activity for oxidation of PCP. Under the optimum conditions, the constructed PCP sensor shows a wide linear range of 0.008 to 10.0 μM. The detection limit is 0.001 μM, which is much lower than the recommended value of PCP in drinking water (0.0037 μM) set by the United States Environmental Protection Agency (US EPA). The sensor was successfully applied for the determination of PCP in vegetable with acceptable recoveries. The method was validated by high-performance liquid chromatography, which provided a new valuable platform for highly sensitive and rapid determination of PCP in real samples.