Electrochemiluminescence Sensor Based on CeO Nanocrystalline for Hg Detection in Environmental Samples.

The excessive concentration of heavy-metal mercury ions (Hg) in the environment seriously affects the ecological environment and even threatens human health. Therefore, it is necessary to develop rapid and low-cost determination methods to achieve trace detection of Hg. In this paper, an Electrochemiluminescence (ECL) sensing platform using a functionalized rare-earth material (cerium oxide, CeO) as the luminescent unit and an aptamer as a capture unit was designed and constructed. Using the specific asymmetric matching between Hg and thymine (T) base pairs in the deoxyribonucleic acid (DNA) single strand, the "T-Hg-T" structure was formed to change the ECL signal, leading to a direct and sensitive response to Hg. The results show a good linear relationship between the concentration and the response signal within the range of 10 pM-100 µM for Hg, with a detection limit as low as 0.35 pM. In addition, the ECL probe exhibits a stable ECL performance and excellent specificity for identifying target Hg. It was then successfully used for spiked recovery tests of actual samples in the environment. The analytical method solves the problem of poor Hg recognition specificity, provides a new idea for the efficient and low-cost detection of heavy-metal pollutant Hg in the environment, and broadens the prospects for the development and application of rare-earth materials.