Electronic Tuning in Reaction‐Based Fluorescent Sensing for Instantaneous and Ultrasensitive Visualization of Ethylenediamine

Abstract

AbstractManipulation of a multi‐physical quantity to steer a molecular photophysical property is of great significance in improving sensing performance. Here, an investigation on how a physical quantity rooted in the molecular structure induces an optical behavior change to facilitate ultrasensitive detection of ethylenediamine (EDA) is performed by varying a set of thiols. The model molecule consisting of a thiol with dual‐carboxyl exhibits the strongest fluorescence, which is ascribed to the electron‐donating ability and prompted larger orbital overlap and oscillator strength. The elevated fluorescence positively corelated to the increased EDA, endowing an ultrasensitive response to the nanomolar‐liquid/ppm‐vapor. A gas detector with superior performance fulfills a contactless and real‐time management of EDA. We envisage this electron‐tuning strategy‐enabled fluorescence enhancement can offer in‐depth insight in advancing molecule‐customized design, further paving the way to widening applications.