title: Ultrasensitive electrochemical detection of secretoneurin based on Pb(2+)-decorated reduced graphene oxide-tetraethylene pentamine as a label.
abstract: In this work, a novel electrochemical immunosensor for the detection of secretoneurin (SN), which uses metal ion functionalised reduced graphene oxide-tetraethylene pentamine (rGO-TEPA) as a label, is reported for the first time. rGO-TEPA contains a large number of amino groups, which makes it an ideal templet for the loading of metal ions. rGO-TEPA-Pb(2+) was employed to immobilise secondary secretoneurin (SN) antibody (Ab2), and the resulting nanocomposite (Ab2-rGO-TEPA-Pb(2+)) was used as a trace tag for signal amplification. A modified electrode consisting of functionalised graphene nanosheets (Au@GS) was used as a substrate to immobilise the antibodies. Under the optimal conditions, the immunoassay exhibited high sensitivity, acceptable stability and reproducibility with a wide linear range from 0.001 to 100ngmL(-1) (R=0.996), and an ultra-low detection limit of 0.33pgmL(-1) (S/N=3). Furthermore, the immunosensor could be employed to detect SN in clinical serum samples. The proposed sensing strategy enriches the electrochemical immunoassay and exhibits potential for the point-of-care diagnostic application of the clinical screening of biomarkers.
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Guolin
authors.initials: G
authors.lastname: Yuan
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Huali
authors.initials: H
authors.lastname: Chen
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Chunyong
authors.initials: C
authors.lastname: Xia
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Liuliu
authors.initials: L
authors.lastname: Gao
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: yuchaom@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005029:Ethylenediamines / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007854:Lead / Q000737:chemistry*; D008832:Microchemistry / Q000295:instrumentation; D009479:Neuropeptides / Q000097:blood* / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results; D053381:Secretogranin II / Q000097:blood* / Q000737:chemistry; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods
chemical_list: D005029:Ethylenediamines; D009479:Neuropeptides; D010087:Oxides; D053381:Secretogranin II; C081159:secretoneurin; D007854:Lead; D006108:Graphite; C034269:tetraethylenepentamine
keywords: Au@graphene nanosheeets; Lead ion; Reduced graphene oxide–tetraethylene pentamine; Secretoneurin