Abstract
A sensitive electrochemiluminescence (ECL) immunosensor was constructed for cardiac troponin I (cTnI) detection by dual quenching effect of folic acid (FA) and in situ generating oxygen (O2) toward the ECL signal of Ru-PAMAM/AuNPs complex. Firstly, polyamidoamine (PAMAM) was linked with tris (4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium(II) dichloride (Ru(dcbpy)32+) via amide bond, and immobilized on gold nanoparticles (AuNPs) by Au-N bond. Then, a strong initial ECL signal was obtained when the Ru-PAMAM/AuNPs complex was assembled onto the modified electrode surface. Furthermore, a novel dual quenching effect of GOD-FA-PtCu3-Ab2 bioconjugate upon the Ru-PAMAM/AuNPs complex-based ECL system was designed to greatly enhance the sensitivity of immunosensor, which was outlined as follows: (1) FA oxidized the excited state PAMAM-Ru(II)* to PAMAM-Ru(III) making the ECL signal quench; (2) Glucose oxidase (GOD) catalyzed the oxidation of glucose to produce H2O2 which could be catalyzed by PtCu3 alloy NCs to in situ generate O2, leading to further quenching of the ECL signal. As a results, the proposed ECL immunosensor exhibited a wide linear detection range of 0.1pg/mL to 0.2ng/mL and a low detection limit of 12 fg/mL (S/N=3).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
