A novel strategy for dual-channel detection of metallothioneins (MTs) and Hg2+ has been proposed. In the absence of Hg2+, the functional chimera aptamer (FCA) designed can form an intact G-quadruplex with flexibility, which was demonstrated to have peroxidase-like activities upon hemin binding. In the presence of Hg2+, the formation of T-Hg2+-T complex results in the conformational switching of FCA, which lost the peroxidase-like activities and cannot catalyze the oxidation of ABTS by H2O2. Upon addition of MTs in this solution, MTs could inter...
