Amines-enriched vertically-ordered silica nanochannels for conductivity-regulated electrochemiluminescence sensing and bacterial metabolism detection.

An innovative amine-enriched vertically-ordered mesoporous silica film (VMSF) on indium tin oxide (ITO) electrodes (A-VMSF/ITO) utilizing an anionic template strategy was successfully developed, resulting in the inner walls of the nanochannel being adorned with well-ordered and abundant tertiary amine groups. In the context of A-VMSF/ITO, the elevated solution conductivity not only facilitates the permeation of Ru(bpy)32+ within nanochannels by compressing the inner electric double layer (EDL), but also greatly improves the electron-transfer efficiency that is critical for enhanced electrochemiluminescence (ECL) generation. Therefore, the A-VMSF/ITO platform exhibited a consistent increase in ECL intensity with rising ionic strength. This property was subsequently employed for monitoring Escherichia coli (E. coli) metabolism, as the metabolic byproducts result in alterations in solution conductivity. Experimental results demonstrated that the ECL signal had closed relationships with the process of E. coli growth, which can be used to evaluate the inhibitory effects of antibiotics. Given its amine-enriched characteristics, A-VMSF/ITO is anticipated to serve as an ideal architecture for nanoconfined ECL research, thereby establishing a robust foundation for homogeneous ECL biosensing.