Detection of radon with biosensors based on the lead(II)-induced conformational change of aptamer HTG and malachite green fluorescence probe.

The aim of this paper is to assemble a new biosensor for detecting the accumulated radon dose in the environment to achieve rapid monitor of radon. Based on the correlation between radon and its stable decay daughter Pb, a biosensor using the lead-induced specific aptamer HTG conformational changes, and the organic dye malachite green (MG) as a fluorescent probe was assembled. In these studies, we explored a novel, sensitive, label-free, fluorescence biosensing method for the detection of both radon and lead. The fluorescence intensity difference has a linear relationship with Pb and the accumulated radon concentration from 6.87 × 10 Bq·h/m to 3.49 × 10 Bq·h/m. The lead and radon detection limits of this method are 6.7 nmol/L and 2.06 × 10 Bq·h/m, respectively. The student's t-test results indicated that the new method was reliable and stable. The detection method is sensitive, accurate, easy to operate, has a wide linear range and is highly selective. In the sampling and determination processes of radon, the radiation harm to human health can be effectively avoided.