Ultrasensitive electrochemiluminescent immunosensing based on trimetallic Au-Pd-Pt/MoS2 nanosheet as coreaction accelerator and self-enhanced ABEI-centric complex

摘要

In this work, an ultrasensitive electrochemiluminescence (ECL) immunosensor for the determination of cystatin C (CYSC) was developed based on the combination of coreaction accelerator amplification and self-enhanced ECL luminophores. Trimetallic Au-Pd-Pt nanoflowers functionalized MoS2 nanosheet (Au - Pd-Pt/MoS2) was used as an efficient coreaction accelerator of ABEL/O-2 ECL system. Besides, the coreactant t-cysteine (L-Cys) was also cross-linked with ABEL to obtain self-enhanced ABEI-centric complex (ABEI-Cys) which was further immobilized onto the surface of Au-Pd-Pt/MoS2 nanosheet, thereby achieving an outstanding signal tagging. Benefiting from the coreaction accelerator amplification of Au - Pd-Pt/MoS2 nanosheet towards ABEL/O-2 ECL system and efficient self-enhanced ABEI-Cys complex, this developed ECL immunosensor for CYSC detection exhibited a wide linear range from 1.0 fg/mL to 5.0 ng/mL with low limit of detection down to 0.35 fg/mL. More importantly, this proposed ECL immunosensing system could remain excellent feasibility in human serum, showing great potential application in clinical diagnosis for proteins monitoring. (C) 2020 Elsevier B.V. All rights reserved.