Photoelectrochemical immunoassay of lipoprotein-associated phospholipase A2 via plasmon-enhanced energy transfer between gold nanoparticles and CdS QDs/g-C3N4
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A facile and feasible photoelectrochemical (PEC) immunoassay based on plasmon-enhanced energy transfer between gold nanoparticles (AuNPs) and CdS quantum dots (QDs)/g-C3N4 nanosheets was developed for the ultrasensitive detection of lipoprotein-associated phospholipase A2 (Lp-PLA2). To construct such a sensing platform, the immunosensor was prepared by immobilizing Lp-PLA2 on a CdS QDs/g-C3N4-modified electrode. A competitive-type immunoreaction was utilized for Lp-PLA2 detection, with AuNP-labeled anti-Lp-PLA2 antibody used as the competitor. Introducing AuNPs with the specific antibody for the antigen target Lp-PLA2 led to heavy quenching of the photocurrent of CdS QDs/g-C3N4 due to the plasmon-enhanced energy transfer between AuNPs and CdS QDs. The quenching efficiency decreased with increasing target Lp-PLA2 concentration. Under optimal conditions, the PEC immunosensor presented a good photocurrent response to the target Lp-PLA2 in the dynamic linear range of 0.01–300 ng mL−1, with a low detection limit of 5.3 pg mL−1. Other biomarkers and natural enzymes did not interfere with response of this system. The reproducibility and accuracy of this method for the analysis of human serum specimens were evaluated, and the results given by the method developed here were found to closely correspond to the results obtained with commercial Lp-PLA2 ELISA kits. Importantly, this protocol offers promise for the development of exciton–plasmon interaction-based PEC detection systems.
KeywordsPhotoelectrochemical immunosensor Lipoprotein-associated phospholipase A2 Gold nanoparticles Exciton–plasmon interaction CdS quantum dots/g-C3N4
Support from the National Natural Science Foundation of China (grant nos.: 81100149, 81470300, and 81301518) is gratefully acknowledged.
Compliance with ethical standards
All procedures performed in this study involving human participants were approved by the Xinqiao Hospital of The Army Medical University and Chonggang General Hospital, and were implemented in accordance with the ethical standards of the Xinqiao Hospital of The Army Medical University and the Chonggang General Hospital ethics committees, as well as with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all of the participants who were included in this study.
Conflict of interest
The authors declare that they have no competing interest.
- 2.Hou C, Ji X. Research progress on mechanisms of ischemic conditioning in cardio-cerebrovascular system. Chin J Cerebrovasc Dis. 2015;12:380–4.Google Scholar
- 3.Xu L, Wang S, Li J. The predictive role of the retinal vascular changes for the cardio-cerebrovascular disease. Ophthalmol China. 2010;19:361–3.Google Scholar
- 9.Shu J, Qiu Z, Lv S, Zhang K, Tang D. Plasmonic-enhancement coupling with defect-engineered TiO2−x: a mode for sensitive photoelectrochemical biosensing. Anal Chem. 2018;90:2425–9.Google Scholar
- 15.Dong Y, Cao J, Wang B, Ma S, Liu Y. Exciton–plasmon interactions between CdS@g-C3N4 heterojunction and Au@Ag nanoparticles coupled with DNAase-triggered signal amplification: toward highly sensitive photoelectrochemical bioanalysis of microRNA. ACS Sustain Chem Eng. 2017;5:10840–8.CrossRefGoogle Scholar
- 23.Zhang K, Lv S, Lin Z, Tang D. CdS:Mn quantum dot-functionalized g-C3N4 nanohybrids as signal generation tags for photoelectrochemical immunoassay of prostate specific antigen coupling DNAzyme concatamer with enzymatic biocatalytic precipitation. Biosens Bioelectron. 2017;95:34–40.CrossRefGoogle Scholar
- 27.Hermanson GT. Bioconjugate techniques. 2nd ed. Rockford: Pierce Biotechnology; 2008. p. 929.Google Scholar
- 28.Zhuang J, Lai W, Xu M, Zhou Q, Tang D. Plasmonic AuNP/g-C3N4 nanohybrid-based photoelectrochemical sensing platform for ultrasensitive monitoring of polynucleotide kinase activity accompanying DNAzyme-catalyzed precipitation amplification. ACS Appl Mater Interfaces. 2015;7:8330–8.CrossRefGoogle Scholar