Triple enrichment using surfactant micelles assembled in nanochannels for emitter, co-reactant, and analyte for high-sensitivity electrochemiluminescence detection of morin

Hard-soft organic–inorganic hybrid interface is constructed by confining surfactant micelles in silica nanochannels. • Surfactant micelles enable triple enrichment of emitter, co-reactant and analyte for signal amplification. • Local concentration of both luminol and dissolved oxygen is enhanced to boost ECL of the luminol/DO system. • Micelle-mediated analyte enrichment allows highly sensitive detection of morin with a low detection limit. • Micellar confinement in nanochannels confers strong interference resistance for analysis in complex matrices. Enhancing the microconcentration of electrochemiluminescence (ECL) emitters and co-reactants at the electrode interface is a potent strategy for ECL signal amplification, while analyte enrichment further improves detection sensitivity. In this work, a hard-soft organic–inorganic hybrid interface incorporating silica nanochannels and surfactant micelles (SM) was developed to achieve triple enrichment of the emitter (luminol), co-reactant (dissolved oxygen-DO), and analyte (antioxidant morin, Mor), resulting in a significant enhancement of ECL and highly sensitive detection. A vertically-ordered mesoporous silica film (VMSF) embedded with cetyltrimethylammonium bromide (CTAB) micelles was fabricated on an affordable and readily accessible indium tin oxide (ITO) electrode via a simple electrochemical-assisted self-assembly (EASA) method. The micelles efficiently concentrate both luminol and DO, leading to a remarkable increase in the ECL signal of the luminol/DO system. Due to the micellar confinement within the VMSF nanochannels, the sensor displayed remarkable resistance to interference. Combined with enhanced ECL and SM-mediated analyte enrichment, sensitive detection of Mor was achieved. Under optimal conditions, the detection range for Mor was from 1 pg/mL to 1 μg/mL, with a detection limit as low as 0.18 pg/mL. This work not only offers an efficient strategy to enhance the ECL of luminol/DO system but also introduces a novel approach for the development of high-performance ECL sensors for trace analysis in complex samples. Download: Download high-res image (170KB) Download: Download full-size image