Competitive Delocalized Charge Transfer Boosted by Solvent Induction Strategy for Survivable Colorimetric Detection of ng-Level Urea.

Achieving sensitive and robust colorimetry is of great significance for on-site chemical detection, but has always been a dilemma or at the expense of practicality. Here, from the perspective of solvent, which is commonly the indispensable medium for chemical sensing, the solvent induction strategy concerning the hydrophobic shielding and hydrophilic bonding solvent cage was proposed considering the configuration branching ratio in the reagent and the prevention of the autoxidation channel. Due to the competitive delocalized charge transfer in the probe and the effective viscous drag in the reagent, remarkable sensing signal concentrating and moisture retention capability were achieved. We expect the present strategy would facilitate the active but robust chemical reaction design and provide a universal methodology for the exploration of high-performance chemical sensors.