Aggregation-Induced Electrochemiluminescence of the Dichlorobis(1,10-phenanthroline)ruthenium(II) (Ru(phen)₂Cl₂)/Tri-n-propylamine (TPrA) System in H₂O–MeCN Mixtures for Identification of Nucleic Acids

Abstract

Aggregation-induced electrochemiluminescence (AIECL) of the dichlorobis­(1,10-phenanthroline)­ruthenium­(II) (Ru­(phen)2Cl2)/tri-n-propylamine (TPrA) system was systematically investigated in H2O–MeCN media. Up to a 120-fold increase in the ECL intensity was observed when the H2O fraction (v%) was changed from 30% to 70%, whereas only an approximately 5.7-fold increase in the corresponding aggregation-induced fluorescence emission was demonstrated. The gradual formation of clusters of Ru­(phen)2Cl2 nanoaggregates along with the increase in the H2O fraction to MeCN, which was verified by dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), was believed to be responsible for the remarkable ECL enhancement. Significantly, the above-mentioned AIECL behavior was found to be very sensitive to the types and sequences of nucleic acids present in solution, which provided an effective and novel strategy for distinguishing RNA from DNA and for differentiating different miRNAs. The present study could have a substantial impact in various research areas, such as molecular sensors, bioimaging probes, organelle-specific imaging, and tumor diagnosis.

Aggregation-induced delayed fluorescence luminogens: the innovation of purely organic emitters for aqueous electrochemiluminescence

“…Very recently, aggregation-induced emission (AIE), a concept launched by Ben Zhong Tang and coworkers, 9,10 has been introduced into the ECL field as new-generation ECL emitter. [11][12][13][14][15][16][17][18][19] Impressively, as for those AIE luminogens, the ubiquitous aggregation caused quenching (ACQ) issue originating from notorious π-π interactions and/or molecular-motion-induced energy dissipation has been well solved via AIE effect. 10 For them, water-insolubility of organic molecules is not a drawback, but even becomes a premise and framework for constructing self-aggregated powder, film or crystalline solidstate emitters featuring much-enhanced PL quantum efficiency (ΦPL).…”

“…Coincidentally, such property is extremely satisfactory for the development of a qualified aqueous ECL emitter, which is the essential demand of the whole ECL technique towards various kinds of applications. 2,20 Starting from the pioneer report on Platinum (II) complex in 2017 by Cola's group, 11 a variety of aggregation-induced electrochemiluminescence (AIECL) emitters have emerged, such as metallic complexes, 18,21,22 metal clusters, 23 AIE organic molecules 12,[14][15][16]24 , carbon dots 17 or polymer dots. 13,25 Meanwhile, ECL bioscience sensing studies using these emitters have also been developed, e.g.…”

Aggregation-Induced Emission in Electrochemiluminescence: Advances and Perspectives

“…Very recently, Gu et al reported the use of dichlorobis(1,10-phenanthroline) ruthenium(II) ([Ru 2 (phen) 2 Cl 2 )] as AIECL luminophore and its application in the sensing and differentiation of nucleic acids [67]. The PL and AIECL emissions of [Ru 2 (phen) 2 Cl 2 ] aggregates, using TPrA as co-reactant, were found to be at a maximum in a 70% water:30% CH 3 CN mixture; at higher water content the increase in the size of the aggregates becomes counterproductive, and a decrease in the intensity of the AIECL is observed (Fig.…”

“…The encapsulation was achieved by the pH-triggered assembly-disassembly of apoFt. The Ir(ppy) 3 @apoFt bioconjugate was used to construct an immunosensor for the biomarker for squamous cell carcinomas CYFRA21, with a good linearity range (1 pg mL −1 -50 ng mL −1 ) and an interesting Adapted with permission from Gu et al [67]. Copyright 2020 American Chemical Society LOD (0.43 pg mL −1 ).…”

Biofuel Cell-Driven Robust Electrochemiluminescence Biosensing Platform

“…Electrochemiluminescence (ECL) is one powerful sensing tool with high sensitivity (<10 –11 M) and outstanding stability for clinical diagnosis, , pharmaceutical analysis, food safety, − and environmental monitoring . The key step was to excite the luminescent molecule [such as Ru­(bpy) 3 , bpy = 2,2′-bipyridine] by external power to form excited states via electron transfer, which could produce emission with coreactants as signal amplification.…”