A simple and sensitive immunoassay for the determination of human chorionic gonadotropin by graphene-based chemiluminescence resonance energy transfer

• Published in: Biosensors & bioelectronics 2014-04, Vol.54, p.72-77
• Main Authors: Lei, Jiuqian, Jing, Tao, Zhou, Tingting, Zhou, Yusun, Wu, Wei, Mei, Surong, Zhou, Yikai
• Format: Article
• Language: English
• Subjects: Antibodies, Immobilized - chemistry; Biological and medical sciences; Biosensing Techniques - methods; Biotechnology; Chemiluminescence resonance energy transfer; Chorionic Gonadotropin - analysis; Chorionic Gonadotropin - blood; Energy Transfer; Fundamental and applied biological sciences. Psychology; Graphene; Graphite - chemistry; Human chorionic gonadotropin; Humans; Immunoassay; Immunoassay - methods; Limit of Detection; Luminescent Measurements - methods; Magnetic separation; Saliva - chemistry
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2013.10.033

In this study, we report a strategy of chemiluminescence resonance energy transfer (CRET) using graphene as an efficient long-range energy acceptor. Magnetic nanoparticles were also used in CRET for simple magnetic separation and immobilization of horseradish peroxidase (HRP)-labeled anti-HCG antibody. In the design of CRET system, the sandwich-type immunocomplex was formed between human chorionic gonadotropin (HCG, antigen) and two different antibodies bridged the magnetic nanoparticles and graphene (acceptors), which led to the occurrence of CRET from chemiluminescence light source to graphene. After optimizing the experimental conditions, the quenching of chemiluminescence signal depended linearly on the concentration of HCG in the range of 0.1mIUmL−1–10mIUmL−1 and the detection limit was 0.06mIUmL−1. The proposed method was successfully applied for the determination of HCG levels in saliva and serum samples, and the results were in good agreement with the plate ELISA with colorimetric detection. It could also be developed for detection of other antigen–antibody immune complexes by using the corresponding antigens and respective antibodies. •Chemiluminescence resonance energy transfer is proposed using graphene as an efficient long-range energy acceptor.•Linear relationship of the proposed method is better than that of the immunoassay using FITC as an acceptor.•Magnetic nanoparticles are used in CRET for magnetic separation and immobilization of antibody.•The proposed method is used to monitor HCG in non-invasive saliva samples.