Three kinds of porphyrin dots as near-infrared electrochemiluminescence luminophores: Facile synthesis and biosensing

Exploring novel near-infrared (NIR) luminophore with highly efficient and benign is strongly anticipated for electrochemiluminescence (ECL) evolution. Here, three kinds of porphyrin dots including 5,10,15,20-tetrakis (4carboxyphenyl) porphyrin (TCPP) dots, ZnTCPP dots and TCPP-based metal organic framework (pMOF) dots have been subtly synthesized for the first time by a universal straightforward exfoliation of bulk porphyrin aggregates or pMOF. These as-designed porphyrin dots perform excellent annihilation ECL activity, also exhibit stable and robust cathodic or anodic NIR ECL properties with different coreactants (potassium peroxydisulfate, hydrogen peroxide or tri-n-propylamine) in aqueous phase. Especially, the ECL efficiency of three kinds of porphyrin dots in S2O82- cathodic system are 56, 44, 39-fold higher than that of the Ru(bpy)32+ standard, respectively. As a new type of ECL luminophores, TCPP dots coupled with a lead ion-dependent DNAzyme and hybridization chain reaction cycle amplification are used to fabricate a label free signal-on ECL biosensor for ultrasensitive detection of Pb2+. A dynamic range from 10 pmol center dot L-1 to 1 mu mol center dot L- 1 with a low limit of detection (1.2 pmol center dot L-1) is obtained. These porphyrin dots provide evidence for the use of organics-based dots as new NIR ECL luminophores for fundamental ECL research, and highlight the significance of small-sized organic nanomaterials in ECL sensing applications.

Automated summary

The study demonstrates the excellent performance and stability of three types of porphyrin dots in electrochemiluminescence, with significantly higher ECL efficiency in the S2O82- cathodic system compared to the standard. Additionally, a biosensor utilizing these porphyrin dots shows ultrasensitive detection of Pb2+.