Facile one-pot synthesis of mulberry-shape silver nanoparticle-doped porphyrin nanoassembly with self-promoted electrochemiluminescence

Abstract

The electrochemiluminescence (ECL) efficiency of porphyrins is limited by the quenching of π–π stacking due to their poor water solubility and inherent instability. Therefore, there is an urgent need to design and explore novel porphyrin luminophores with high ECL efficiency, which presents a significant challenge. In this work, a facile one-pot strategy was developed to synthesize a self-promoter-doped porphyrin-based ECL luminophore with high ECL efficiency for the first time. The silver nanoparticle (AgNPs)-doped meso-tetra(4-carboxyphenyl) porphyrin (TCPP) (AgNPs@TCPP) nanoassembly was prepared by inducing TCPP assembly using Ag nanoseeds produced by the reduction of silver nitrate with N,N-dimethylformamide. In this process, AgNPs could coordinate with the carboxyphenyl groups at the terminus of TCPP and the pyrrole nitrogen of TCPP. The resulting AgNPs@TCPP nanoassembly demonstrated superior ECL performance using K₂S₂O₈ as a co-reactant, with an ECL efficiency of 217%, significantly higher than that of previously reported sodium dodecyl sulfate-assisted TCPP aggregate (92.3%) and cetyltrimethylammonium bromide-assisted TCPP aggregate (57.5%). The self-promoted and highly efficient ECL of the AgNPs@TCPP nanoassembly was attributed to overcoming the ECL quenching due to bad TCPP aggregation by virtue of Ag nanoseeds induced TCPP assembly and the self-promoted ECL amplification by doping AgNPs with excellent conductivity. These findings offer a new approach for exploring highly efficient porphyrin-based ECL luminophores, thereby expanding the applications of porphyrins in ECL.