title: A new immunoassay of serum antibodies against Peste des petits ruminants virus using quantum dots and a lateral-flow test strip.
abstract: A fast and ultrasensitive test-strip system combining quantum dots (QDs) with a lateral-flow immunoassay strip (LFIAS) was established for detection of Peste des petits ruminants virus (PPRV) antibody. The highly luminescent water-soluble carboxyl-functionalized QDs were used as the signal output and were conjugated to streptococcal protein G (SPG), which was capable of binding to immunoglobulin G (IgG) from many species through an amide bond to capture the target PPRV IgGs. The PPRV N protein, which was immobilized on the detection zone of the test strip, was expressed by transfecting recombinant Bacmid-PPRV-N with Lipofect into Sf9 insect cells. When exposed to PPRV IgG, QD-SPG bound to PPRV N protein, resulting in the formation of a complex that subsequently produced a bright fluorescent band in response to 365 nm ultraviolet excitation. Sensitivity evaluation showed that the QD-LFIAS limit of detection (LOD) for PPRV antibody was superior to competitive enzyme-linked immunosorbent assay (c-ELISA) and the immunochromatographic strip. No cross reaction was observed when the positive sera of bluetongue virus, canine distemper virus, goat pox virus, and foot-and-mouth disease virus were tested. Further evaluation using field samples indicated that the diagnostic specificity and sensitivity of the QD-LFIAS was 99.47 and 97.67 %, respectively, with excellent agreement between QD-LFIAS and c-ELISA. The simple analysis step and objective results that can be obtained within 15 min indicate that this new method shows great promise for rapid, sensitive detection of PPRV IgG for onsite, point-of-care diagnosis and post vaccination evaluation (PVE). Graphical Abstract Ultrasensitive fluorescent QD immunochromotography in combination with recombinant PPRV N protein could be used to detect PPRV antibody in serum.
authors: Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.|Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Si
authors: S
authors: Cheng
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Jie
authors: J
authors: Sun
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Junxing
authors: J
authors: Yang
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Jianqiang
authors: J
authors: Lv
authors: Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, China.
authors: Feng
authors: F
authors: Wu
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Yanxing
authors: Y
authors: Lin
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Lishan
authors: L
authors: Liao
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Yiyou
authors: Y
authors: Ye
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China.
authors: Chenfu
authors: C
authors: Cao
authors: Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China. fanglr@mail.hzau.edu.cn.
authors: Liurong
authors: L
authors: Fang
authors: Shenzhen Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China (SZCIQ), Shenzhen, Guangdong, 518045, China. 13922861650@163.com.
authors: Qunyi
authors: Q
authors: Hua
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D004867:Equipment Design; D006041:Goats; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D029021:Peste-des-Petits-Ruminants / Q000097:blood* / Q000276:immunology; D018107:Peste-des-petits-ruminants virus / Q000276:immunology* / Q000302:isolation & purification; D019095:Point-of-Care Systems; D045663:Quantum Dots / Q000737:chemistry*; D011934:Reagent Strips / Q000032:analysis*; D061987:Sf9 Cells
chemical_list: D000914:Antibodies, Viral; D011934:Reagent Strips
keywords: Field test; Lateral-flow immunoassay strip; Peste des petits ruminants virus; Quantum dots