A reaction-type receptor for the multi-feature detection of Hg2+ in water and living cells

Abstract

A vital challenge in designing optical and redox-active receptors lies in coupling a specific recognition center with a valid response system to facilitate multi-feature detection. Herein, we present a reaction-type receptor, which incorporates the ferrocenyl group into the rhodamine B fluorophore via a well-defined acylthiourea bridge, for the multi-model analysis of Hg²⁺ in water and living cells. This receptor was successfully used to efficiently detect Hg²⁺ in an aqueous medium by chromogenic, fluorogenic, and electrochemical assessments and exhibited a low detection limit (1.60 × 10⁻⁸ M) and fast response time (<3 min). Especially, it also acted as a competent fluorescent probe for monitoring Hg²⁺ in living cells. A plausible sensing mechanism has been proposed and rationalized based on theoretical calculations.