Selective dual detection of Hg²⁺ and TATP based on amphiphilic conjugated polythiophene-quantum dot hybrid materials

The design of multifunctional sensors based on biocompatible hybrid materials consisting of conjugated polythiophene-quantum dots for multiple environmental pollutants is a promising strategy for the development of new monitoring technologies. Herein, we present a new approach for the "on-off-on" sensing of Hg²⁺ and triacetone triperoxide (TATP) based on amphiphilic polythiophene-coated CdTe QDs (PQDs, PLQY ∼78%). The emission of the PQDs is quenched by Hg²⁺ ions via electron transfer interactions. Based on the strong interaction between TATP and Hg²⁺ ions, the addition of TATP to the PQD-Hg²⁺ complex results in a remarkable recovery of the PQD emission. Under the optimized conditions, the PQD sensor shows a good linear response to Hg²⁺ and TATP with detection limits of 7.4 nM and 0.055 mg L^-1, respectively. Furthermore, the "on-off-on" sensor demonstrates good biocompatibility, high stability, and excellent selectivity in the presence of other metal ions and common explosives. Importantly, the proposed method can be used to determine the level of Hg²⁺ and TATP in environmental water samples.