Dual resonance energy transfer in triple-component polymer dots to enhance electrochemiluminescence for highly sensitive bioanalysis

Abstract

Polymer dots (Pdots) have become a type of attractive illuminant for electrochemiluminescence (ECL). However, the low ECL efficiency severely limits their practicability. Here, we design a dual intramolecular resonance energy transfer (RET) mechanism with newly synthesized triple-component Pdots to achieve great ECL enhancement. This mechanism efficiently shortens the path of energy transmission, thus greatly promoting the ECL amplification by 380 and 31 times compared to systems with no and single RET, and results in a relative ECL efficiency of 23.1% (vs. 1 mM Ru(bpy)3²⁺). Using metal–organic frameworks to carry the triple-component Pdots, a highly luminescent probe is proposed. By integrating the probe with target-mediated enzymatic circulation amplification and DNA arrays, a highly sensitive ECL imaging method is designed for simultaneous visual analysis of two kinds of proteins, mucin 1 and human epidermal growth factor receptor 2, on living cells, which exhibited linear ranges of 1 pg mL⁻¹ to 5 ng mL⁻¹ and 5 pg mL⁻¹ to 10 ng mL⁻¹ with limits of detection of 1 pg mL⁻¹ and 5 pg mL⁻¹, respectively. The proposed strategy showed promising application in bioanalysis.