Reaction-based conjugated polymer fluorescent probe for mercury(ii): good sensing performance with “turn-on” signal output

Abstract

Based on a Hg²⁺-promoted deprotection reaction of dithioacetal, the conjugated polymer PDT was designed. PDT exhibited significant fluorescence enhancement along with an apparent red-shift upon the addition of mercury ions. Due to the specific chemical reaction, the response was very fast with good selectivity towards Hg²⁺. Other metal ions, including K⁺, Na⁺, Li⁺, Ba²⁺, Mg²⁺, Pb²⁺, Ca²⁺, Mn²⁺, Fe²⁺, Co²⁺, Fe³⁺, Cu²⁺, Ni²⁺, Al³⁺, Cd²⁺, Cr³⁺, and Zn²⁺, had nearly no influence on the sensing process. Moreover, PDT showed high sensitivity with the detection limit of 1.0 × 10⁻⁶ mol L⁻¹ and 1 × 10⁻⁵ mol L⁻¹ in solution and as test strips, respectively, as a result of the molecular wire and signal amplification effects.