New Signal Probe Integrated with ABEI as ECL Luminophore and Ag Nanoparticles Decorated CoS Nanoflowers as Bis-Co-Reaction Accelerator to Develop a Ultrasensitive cTnT Immunosensor

• Published in: Journal of the Electrochemical Society 2018, Vol.165 (14), p.B686-B693
• Main Authors: Yi, Ting-Quan, Gong, Wei, Lei, Yan-Mei, Zeng, Wei-Jia, Chai, Ya-Qin, Yuan, Ruo, Zhuo, Ying
• Format: Article
• Language: English
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.0381814jes

In this work, Ag nanoparticles (Ag NPs) decorated CoS nanoflowers (CoS NFs) were firstly used as bis-coreaction accelerator for signal amplification to establish an highly sensitive electrochemiluminescence (ECL) immunosensor for cardiac troponin T (cTnT) detection. Due to the synergistic catalysis between CoS NFs and Ag NPs, the decomposition rate of the co-reaction reagent H2O2 was largely improved, generating more ROS for signal amplification. Using the N-(4-aminobutyl)-N-ethylisoluminol (ABEI) as ECL luminophore, a new signal tag was acheived according to the assembly of ABEI functionalized Ag NPs (ABEI-Ag) on the CoS NFs via Ag-S bond, which integrated with the ECL luminophore and bis-co-reaction accelerator. In addition, to fabricate sensing interface, primary antibodies (Ab1) was immobilized on the glassy carbon electrode which decorated with Au nanoparticles (Au NPs), almost providing a zero background signal. As a result, this developed immunosensor for cTnT possessed a linear range from 0.1 fg mL−1 to 100 pg mL−1 and the limit of detection down to 0.03 fg mL−1 for ultrasensitive detection of cTnT, which was expected to be applicable to cTnT detection in clinic acute myocardial infarction.