title: Highly sensitive fluorescent immunoassay of human immunoglobulin G based on PbS nanoparticles and DNAzyme.
abstract: This paper reports a highly sensitive fluorescent immunoassay for the detection of human immunoglobulin G based on PbS nanoparticles and DNAzyme. A sandwich immunoassay format was performed on a microtiter plate. Goat anti-human IgG was coated onto the polystyrene microtiter plate. The human IgG analyte was first captured by the goat anti-human IgG, and then sandwiched by a goat anti-human IgG antibody labeled with PbS nanoparticles. After being dissolved with HNO3, the released Pb(2+) made the substrate chain of the DNAzyme labeled with the fluorophore dissociate from the enzyme strand of the DNAzyme labeled with the quencher, which resulted in fluorescence recovery. Then, the human IgG could be detected indirectly from the fluorescent signals. Under the optimized conditions, the linear range of the developed immunosensor was from 1 ng mL(-1) to 10 μg mL(-1) with a detection limit of 0.8 ng mL(-1). This immunosensor could be used to detect the amount of human IgG in human serum samples.
authors.affiliation: State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P.R. China.
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Huang Fu
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Hao
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: Wu
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Qiao
authors.forename: Zi
authors.initials: Z
authors.lastname: Yi
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Li
authors.forename: Xia
authors.initials: X
authors.lastname: Chu
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D021881:DNA, Catalytic / Q000737:chemistry*; D005455:Fluorescent Antibody Technique / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007854:Lead / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles; D013440:Sulfides / Q000737:chemistry*
chemical_list: D017931:DNA Primers; D021881:DNA, Catalytic; D007074:Immunoglobulin G; D013440:Sulfides; C018391:lead sulfide; D007854:Lead