title: Enhanced immunoassay for porcine circovirus type 2 antibody using enzyme-loaded and quantum dots-embedded shell-core silica nanospheres based on enzyme-linked immunosorbent assay.
abstract: Boosting the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is significant to the early clinical diagnosis of various diseases. Here, we developed a versatile immunosensor using silica nanospheres as carriers for sensitive detection of porcine circovirus type 2 (PCV2) antibody. With HRP enzyme covalently immobilized on the silica nanospheres and CdSe nanocrystals embedded inside, these signal probes were successfully utilized in the sensitive detection of PCV2 antibody by ELISA, fluorometry and square-wave voltammetry (SWV). To further demonstrate the performance of the immunosensor, Human IgG (HIgG) was used as a model analyte. Since more HRP and CdSe QDs were loaded, 5-, 200- and 400-fold enhancements in amplified ELISA, fluorometry and voltammetry responses for HIgG could be achieved compared to conventional ELISA. The respective detection limits of theses methods for HIgG were 3.9, 0.1 and 0.05 ng mL(-1) with a RSD below 5% for amplified ELISA, fluorescence and SWV measurements. Additionally, a 100-fold improvement was obtained in the detection sensitivity for PCV2 antibody immunoassay. The versatile immunosensor exhibits good sensitivity, stability and reproducibility, suggesting its potential applications in clinical diagnostics.
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Long
authors: L
authors: Wu
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Xuepu
authors: X
authors: Li
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Kang
authors: K
authors: Shao
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Shiyi
authors: S
authors: Ye
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Chen
authors: C
authors: Liu
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors: Chenjun
authors: C
authors: Zhang
authors: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China. Electronic address: hyhan@mail.hzau.edu.cn.
authors: Heyou
authors: H
authors: Han
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis* / Q000276:immunology; D019187:Cadmium Compounds / Q000737:chemistry; D017925:Circovirus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D057230:Limit of Detection; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D018036:Selenium Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013552:Swine / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D019187:Cadmium Compounds; D007074:Immunoglobulin G; D018036:Selenium Compounds; D012822:Silicon Dioxide; C058667:cadmium selenide
keywords: Enzyme; Enzyme-linked immunosorbent assay; Immunosensor; Quantum dots; Silica nanosphere