A novel biosensor for the rapid and high-sensitive detection of mercury based on cleavable phosphorothioate RNA probe

Abstract

Since mercury is one of the most toxic heavy metals in water, its detection is critical for environmental protection. Various biosensors based on T-Hg2+-T sensing strategies have been developed; however, their mechanisms are highly dependent on the buffer conditions and are not suitable for the rapid high-throughput analysis of many complex water samples. In this work, a self-assembled biosensor for the high-throughput detection of Hg2+ based on a cleavable PS-RNA-modified probe and homogeneous photochemical chemiluminescence assay was developed. In the presence of Hg2+, the probe was cleaved, and the singlet oxygen channel was destroyed, which decreased the fluorescence signal. This biosensor is highly selective for Hg2+, with a limit of detection of 1.4 nM (S/N = 3) in a linear range of 5 nM - 5 μM (R2 = 0.991). The recoveries of standard addition methods in different water samples indicate that this feasible, simple method is a promising tool to monitor mercury ions in environmental applications.