|A sensitive electrochemiluminescence biosensor for assay of cancer biomarker (MMP-2) based on NGQDs-Ru@SiO2 luminophore.|
Fan X, Wang S, Liu H, Li Z, Sun Q, Wang Y, Fan X.
Talanta. 2022; 236(): 122830
A sensitive biosensor that can be used for the determination of matrix metalloproteinase 2 (MMP-2) was proposed. The biosensor was developed by using an excellent self-enhanced nanocomposites as an illuminant and a peptide as a recognition element. For the electrostatic attraction between Ru(bpy)3(2+) and nitrogen-doped graphene quantum dots (NGQDs), the self-enhanced electrochemiluminescence (ECL) nanocomposites of NGQDs-Ru(bpy)3(2+)-doped silica nanoparticles (NGQDs-Ru@SiO2) were synthesized through a simple sol-gel process. Then, a specific peptide (labeled sulfhydryl) was combined with the self-enhanced ECL nanocomposites (carboxyl in NGQDs) via acylation reaction to obtain the peptide-NGQDs-Ru@SiO2 nanoprobe, which was fabricated onto the gold electrode surface via Au-S bond. The peptide of the ECL nanoprobe was exposed to cleavage in the presence of MMP-2, which caused the signal substance to move farther away from the electrode, leading to a decrease of the ECL signal. The proposed NGQDs-Ru@SiO2-labeled peptide ECL biosensor displayed a lower detection limit of 6.5 pg mL(-1) than those of reported ECL methods. The proposed biosensor provided an outlook for future applications in other disease-associated biomarkers. CI - Copyright (c) 2021 Elsevier B.V. All rights reserved.