Multifunctional Zinc Oxide Promotes Electrochemiluminescence of Porphyrin Aggregates for Ultrasensitive Detection of Copper Ion

Abstract

The design and exploration of highly efficient organic luminophores for an electrochemiluminescence (ECL) sensor is a fascinating and promising subject. Herein, we present a surfactant-assisted self-assembly of 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) J-aggregate as a robust organic luminophore to construct the solid-state ECL sensing platform with significantly enhanced and constantly stable signals, by using peroxydisulfate (S2O8 2–) as the coreactant, and l-cysteine capped zinc oxide nanoflowers (ZnO@Cys NFs) as the multifunctional energy donor and coreactant accelerator. Compared with TCPP monomer, this TCPP J-aggregate possesses a unique aggregation-induced electrochemiluminescence (AIECL) performance, which results in 5-fold enhancement in red-light ECL emission at 675 nm. The resonance energy transfer from the ZnO@Cys NFs (energy donor) to the TCPP J-aggregate (energy acceptor) substantially improves the ECL intensity and stability. ZnO@Cys NFs have also been used as a coreactant accelerator to promote the conversion of more S2O8 2– into SO4 •–. The corresponding ECL mechanism has been investigated by UV–vis absorption spectrum, photoluminescence, ECL, and density functional theory. Since l-cysteine on ZnO@Cys NFs can efficiently realize bidentate chelation with Cu2+, the proposed ECL sensor shows a highly selective and sensitive quenching effect for the detection of Cu2+ with a wide linear range from 1.0 pmol·L–1 to 500 nmol·L–1 and a detection limit of 0.33 pmol·L–1, paving a bright research direction for the development of TCPP aggregates in ECL field.

Self-Luminescent Lanthanide Metal–Organic Frameworks as Signal Probes in Electrochemiluminescence Immunoassay

“…The working electrode (GCE) was buffed to be slippy with aluminum oxide power and ultrasonic cleaned with ethanol and ultrapure water that was dried thoroughly with N 2 before use. 20,21 A total of 10 μL of flower-like NiFe complex/Ab 1 /BSA basal conjugate was directly dripped onto the surface of the GCE and dried at 4 °C. Afterward, a series of concentrations of cyfra21-1 were modified on the GCE surface, which was coated with NiFe complex/Ab 1 /BSA bioconjugate.…”

Aggregation-Induced Emission in Electrochemiluminescence: Advances and Perspectives

“…Thus, the choice of methodologies that suppress the formation of the π-stacked H-aggregation and favor the displaced J-aggregates is a strategy that can promote the AIECL in porphyrin-based luminophores. Using surfactant-assisted synthesis, Fu and collaborators [56] obtained the J-aggregates of 5,10,15,20-tetrakis (4-carboxyphenyl)porphyrin (TCPP) that by an R-O mechanism, using peroxydisulfate as co-reactant, displays AIECL. This system was applied in the construction of a composed platform for the sensing of Cu 2+ .…”

An Ultra‐sensitive Electrochemiluminescent Detection of Carcinoembryonic Antigen Using a Hollowed‐out Electrode

“…Since the excited species in ECL reaction are generated by electrochemical stimuli rather than by light excitation that occurs in fluorescence methods, ensuring the minimization of background light, ECL protocols generally display an improved signal-to-noise ratio. ECL is the combination of electrochemical and luminescence techniques, taking advantage of relatively low-cost instrumentation, flexible approach of electrode modification, highly sensitive and selective detection, and thus it has been extensively applied to detect heavy metal ions [17,18], analyze nucleic acids [19,20], investigate cells and tumor markers [2,21]. For those reasons, ECL immunosensor is a powerful and versatile tool for trace CEA analysis.…”