Construction Of Novel Solid-State Electrochemiluminescence Sensors For Environmental Pollutants Detection

Electrochemiluminescence?ECL? detection has a high sensitivity. The merits of fast analysis, simplicity and wide linearity range are highlighted. Therefore, the ECL sensors can be used to detect and trace environmental pollutants such as persistent organic pollutants and heavy-metal ions. However, most of reported ECL systems focus on single functional materials, resulting in poor response signal which does not satisfy the requirement of practical application. Furthermore, these ECL systems are not immobilized, so it is difficult to reuse. How to fabricate green, effective and reusable ECLs is a key. In this thesis, three kinds of solid-state ECL sensors were constructed for effectively detecting pentachlorophenol and heavy-metal ions. The immobilized ECL sensors are regenerable without waste of resources, which could provide new insight into detection of environmental pollutants. The specific research work is divided into the following several aspects:?1? Electrochemiluminescence detection of pentachlorophenol?PCP? based on Au nanoclusters/graphene?Au NCs/GR? hybrid with S2O82- as coreactant: graphene served as both immobilization and amplification platform for Au NCs, which could not only enhance the detection sensitivity, but solve the non-recyclable problem. The interaction between PCP and the Au*+ results in a sensitive change in the ECL intensity, with a unprecedented sensitivity reaching 1.0 × 10-14 M and have a wide linear relationship?1.0 × 10-14–1.0 × 10-10 M?. This sensor has the advantages such as avoiding complicated design, low toxicity, regenerability, and high sensitivity, which could be a simpler and easier sensing approach to trace environmental pollutants and a promising alternative method for the emergency and routine monitoring of the PCP in real water samples.?2? Electrochemiluminescence detection of copper ions(Cu²⁺) with use of Pt nanoclusters/graphene?Pt NCs/GR? hybrid by one-step electrodepostion: the ECL intensity of Pt NCs/GR is much higher than that of Pt NCs. It suggests that the GR would greatly enhance the sensitivity of ECL detection and accelerate the transfer of electron between Pt NCs and coreactant. Due to the high specific surface area of Pt NCs and GR, the copper ions in the solution were easily absorbed on the surface of modified electrode to be detected, demonstrating a high sensitivity of the method. Under the optimal conditions, the limit of detection would be 1.0 × 10-7 gL-1.?3? Cadmium sulfide?CdS? nanofibers were prepared by hydrothermal method ECL detectionof lead ions(Pb²⁺) : in order to reduce the coagulation effect by nanoparticles, the CdS nanofibers can effectively prevent the coagulation effect and realize the quick detection of lead ion. The proposed ECL sensor exhibits well in Pb²⁺-selective sensing with a wide linear relationship?1.0 × 10-10–1.0 × 10-6 gL-1?, with the correlation coefficient of 0.994. The limit of detection?S/N = 3? is 1.0 × 10-10 gL-1. Due to the stability of CdS nanofibers, the prepared sensor shows a highly stable performance and good repeatability in detecting Pd²⁺.