Porous Complex-Mediated Dual Emission of Porphyrins for the Electrochemiluminescence Bioassay

Abstract

Although porphyrins make up a promising class of electrochemiluminescence (ECL) luminophors, their aggregation-caused quenching (ACQ) characteristics lead to inferior ECL efficiency (ΦECL). Furthermore, current application of porphyrins is limited to cathodic emission. This work creatively exploited a cage-like porous complex (referred to as SWU-1) as the microreactor to recede the ACQ effect while modulating dual ECL emission of meso-tetra­(4-carboxyphenyl)­porphine (TCPP), which self-assembled with SWU-1 to form TCPP@SWU-1 nanocapsules (TCPP@SWU-1 NCs). As the microreactor, SWU-1 not only effectively constrained TCPP aggregation to improve electron–hole recombination efficiency but also improved stability of anion and cation radicals, thus significantly enhancing the dual emission of TCPP. Compared with TCPP aggregates, the resulting TCPP@SWU-1 NCs exhibited significantly enhanced anodic and cathodic emission, and their ΦECL was increased by 8.7-fold and 3.9-fold, respectively. Furthermore, black hole quencher-2 (BHQ2) can simultaneously quench anodic and cathodic signals. TCPP@SWU-1 NCs coupling BHQ2 conveniently achieved an ECL ratio detection of miRNA-126, and the limit of detection (S/N = 3) was 4.1 aM. This work pioneered the development of the cage-like porous complex SWU-1 as the microreactor to alleviate defects of the ACQ effect and mediate dual emission of TCPP. The coupling of dual-emitting TCPP@SWU-1 NCs and dual-function moderator BHQ2 created a novel single-luminophor-based ratio system for bioanalysis and provided a promising ECL analysis approach for miRNA-126.

Silver Nanoparticles In Situ Enhanced Electrochemiluminescence of the Porphyrin Organic Matrix for Highly Sensitive and Rapid Monitoring of Tetracycline Residues

“…Li’s team proposed a new zirconium metal–organic framework (Zr-DPA@TCPP) as a single luminophore, which showed synchronous anodic and cathodic ECL signals . Chen et al exploited a cage-like porous complex as the microreactor to attenuate the aggregation-caused quenching effect of meso-tetra­(4-carboxyphenyl) porphine . It is not hard to see that regulating the molecular framework of porphyrins is an ideal strategy for obtaining a high efficiency of ECL.…”

Dual-Ligand Ruthenium Coordination Polymer-Derived Self-Enhanced Electrochemiluminescent Emitters for Sensitive Detection of Procalcitonin

“…Electrochemiluminescence (ECL) has excellent spatiotemporal controllability in the luminous intensity due to the efficient integration of electrochemistry and chemiluminescence, − so it has been broadly applied in clinical diagnosis and related medical examination. − Tris­(2,2′-bipyridyl)-ruthenium­(II) (Ru­(bpy) 3 2+ ) and its derivatives are frequently used as luminophores in classical ECL due to their good regenerability and strong ECL signal. Early Ru-based ECL systems in the homogeneous phase were expensive and had limited luminescence efficiency .…”