title: An amplified electrochemiluminescent aptasensor using Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites as a signal enhancement tag.
abstract: A novel electrochemiluminescent (ECL) signal tag of Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites (AuNPs/TSC-PTC/C60NPs) was developed for thrombin (TB) aptasensor construction based on the peroxydisulfate/oxygen (S2O8(2-)/O2) system. For signal tag fabrication, the C60 nanoparticles (C60NPs) were prepared and then coated with 3,4,9,10-perylene tetracarboxylic acid (PTCA) by π-π stacking interactions. Afterwards, thiosemicarbazide (TSC) was linked with PTCA functionalized C60NPs via amidation for further assembling Au nanoparticles (AuNPs). Finally, detection aptamer of thrombin (TBA 2) was labeled on the ECL signal amplification tag of AuNPs/TSC-PTC/C60NPs. Herein, TSC, with the active groups of -NH2 and -SH, was selected and introduced into the ECL S2O8(2-)/O2 system for the first time, which could not only offer the active groups of -SH to absorb AuNPs for TBA 2 anchoring but also remarkably enhance the ECL signal of the S2O8(2-)/O2 system by the formation of TSC-PTC/C60NPs for signal amplification. Meanwhile, the sensing interface of a glassy carbon electrode (GCE) was modified by AuNPs/graphene (AuNPs/GR) nanocomposites with the large specific surface area and the active sites, followed by immobilization of thiol-terminated thrombin capture aptamer (TBA 1). With the formation of the sandwich-type structure of TBA 1, TB, and TBA 2 signal probes, a desirable enhanced ECL signal was measured in the testing buffer of an S2O8(2-)/O2 solution for detecting TB. The aptasensor exhibited a good linear relationship for TB detection in the range of 1 × 10(-5)-10 nM with a detection limit of 3.3 fM.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China. yingzhuo@swu.edu.cn yqchai@swu.edu.cn.
authors.forename: Meng-Nan
authors.initials: MN
authors.lastname: Ma
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan