Ultrasensitive detection of pentachlorophenol based on enhanced electrochemiluminescence of Au nanoclusters/graphene hybrids

Pentachlorophenol (PCP) is an environmental pollutant of serious concern due to its high toxicity and long persistence property. Fast and sensitive detection of PCP is therefore of great interest. Here, for the first time, a novel electrochemiluminescence (ECL) sensor based on Au nanoclusters/ graphene (Au NCs/GR) hybrid has been constructed for the detection of PCP, with S2O82- as coreactant. GR facilitates both Au- and SO(4)(-)production, and a high yield of the excited Au NCs (Au*(+)) produces due to the presence of Au- and SO4-. The interaction between PCP and the Au*(+) results in a sensitive change in the ECL intensity, with an unprecedented sensitivity reaching 1.0 x 10(-14) M concentration in a wide linear range from 1.0 x 10(-14) M to 1.0 x 10(-10) M. Other compounds which cannot be oxidized by the Au*(+) show little interference on the detection of PCP. The obtained ECL sensor is low toxicity and regenerable, furthermore, the practicability of the ECL sensor in real water sample is also tested, which shows satisfactory results. (C) 2014 Elsevier B.V. All rights reserved.