Abstract:
Reliable and ultrasensitive detection of mercury ions is of paramount importance for toxicology assessment, environmental protection, and human health. Herein, we present a novel optoelectronic approach based on nano architectonics of small-molecule templated DNA system that consists of an adenine (A)-conjugated small organic semiconductor (BNA) and deoxyribo-oligothymidine (dT(n)). This mutually templated dynamic chiral coassembly system (BNAn-dT(n)) with tunable chiroptical, morphological, and electrical properties is tapped in to enable ultrasensitive and selective detection of inorganic and organometallic mercury in water. We observe a rapid transformation of the BNA(n)-dT(n) coassembly into a metallo-DNA duplex [dT-Hg-dT](n), in the presence of mercury, which is utilized for a chiro-optical and conductivity-based rapid and subnanomolar sensitivity (>= 0.1 nM, 0.02 ppb) to mercury ions in water (similar to 100 times lower than United States Environmental Protection Agency tolerance limit). This ultrasensitive detection of inorganic and organometallic mercury is driven by a novel chemical design principle that allows strong mercury thymine interaction. This study is anticipated to inspire the development of future templated DNA nanotechnology-based optoelectronic devices for the rapid and ultrasensitive detection of numerous other toxic analytes.
