Light Scattering and Luminophore Enrichment-Enhanced Electrochemiluminescence by a 2D Porous Ru@SiO2 Nanoparticle Membrane and Its Application in Ultrasensitive Detection of Prostate-Specific Antigen

Electrochemiluminescence (ECL) by virtue of its controllability and versatility has emerged as a significant tool in bioassay, but how to integrate it with other (nano)materials and further break the limit of sensitivity for ultrasensitive detection still possess tremendous potential. Herein, a close-packed Ru@SiO2 NP nanomembrane that serves as an enhanced substrate and luminophore enricher simultaneously was constructed by the liquid-liquid interface self-assembly method and applied for ECLenhanced bioassay. The developed ECL electrode obtained similar to 600-fold enhancement on ECL intensity compared with the bare ITO electrode and similar to 21-fold enhancement compared with the SiO2 NP nanomembrane electrode due to the dramatic light scattering of the 2D SiO2 NPs and the enrichment of Ru(bpy)(3)(2+) molecules on the surface of the Ru@SiO2 NP nanomembrane electrode. Based on the fascinating Ru@SiO2 NP nanomembrane platform, we further constructed a label-free immunosensor for the detection of prostate-specific antigen (PSA). The as-fabricated Ru@SiO2-nanomembrane ECL immunosensor exhibited good stability and performed ultrasensitive detection with an utmost low detection limit of 0.169 fg.mL(-1) (signal/noise = 3). Our work puts forward an effective solution benefiting for further improving ECL performance for ultrasensitive bioassays.

Automated summary

This study successfully constructed a Ru@SiO2 NP nanomembrane platform to improve ECL performance for ultrasensitive bioassays. Through enhancing light scattering and molecular enrichment, the ECL intensity was significantly improved.