title: Nanogold-penetrated poly(amidoamine) dendrimer for enzyme-free electrochemical immunoassay of cardiac biomarker using cathodic stripping voltammetric method.
abstract: Methods based on immunoassays have been developed for cardiac biomarkers, but most involve the low sensitivity and are unsuitable for early disease diagnosis. Herein we design an electrochemical immunoassay for sensitive detection of myoglobin (a cardiac biomarker for acute myocardial infarction) by using nanogold-penetrated poly(amidoamine) dendrimer (AuNP-PAMAM) for signal amplification without the need of natural enzymes. The assay was carried out on the monoclonal mouse anti-myoglobin (capture) antibody-anchored glassy carbon electrode using polyclonal rabbit anti-myoglobin (detection) antibody-labeled AuNP-PAMAM as the signal tag. In the presence of target myoglobin, the sandwiched immunocomplex could be formed between capture antibody and detection antibody. Accompanying AuNP-PAMAM, the carried gold nanoparticles could be directly determined via stripping voltammetric method under acidic conditions. Under optimal conditions, the detectable electrochemical signal increased with the increasing target myoglobin in the sample within a dynamic working range from 0.01 to 500 ng mL(-1) with a detection limit of 3.8 pg mL(-1). The electrochemical immunoassay also exhibited high specificity and good precision toward target myoglobin. Importantly, our strategy could be applied for quantitative monitoring of myoglobin in human serum specimens, giving well matched results with those obtained from commercialized enzyme-linked immunosorbent assay (ELISA) method.
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Clinical Biochemistry, Laboratory Sciences, Third Military Medical University, Chongqing 400038, PR China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Liang
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Cui
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
authors.forename: Jiabei
authors.initials: J
authors.lastname: Li
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Yu
authors.affiliation: Institute of Cardiovascular Diseases, XinQiao Hospital, Third Military Medical University, Chongqing 400037, PR China. Electronic address: amiodarone@163.com.
authors.forename: Lan
authors.initials: L
authors.lastname: Huang
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D050091:Dendrimers / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles; D011073:Polyamines / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D050091:Dendrimers; C531249:Poly(amidoamine); D011073:Polyamines
keywords: Cathodic stripping voltammetry; Electrochemical immunosensor; Enzyme-free immunoassay; Gold nanoparticles; Myoglobin; Poly(amidoamine) dendrimer