title: A novel dynamic flow immunochromatographic test (DFICT) using gold nanoparticles for the serological detection of Toxoplasma gondii infection in dogs and cats.
abstract: A novel dynamic flow immunochromatographic test (DFICT) is proposed for rapid assay utilizing Toxoplasma gondii as a model. The test is based on a proprietary technology that combines the principles of immunochromatography and fluid dynamics. Gold nanoparticles conjugated to staphylococcal protein A (SPA) were prepared in liquid form and used as signal vehicles. T. gondii-specific recombinant antigens and SPA were sprayed onto a nitrocellulose membrane in strips at positions designated as T and C, respectively. The DFICT is performed by applying a 100 µL aliquot of liquid gold-SPA conjugate to the reagent hole and a 5 μL aliquot of serum sample to the sample hole. The results were observable within 5 min by the naked eye. The lowest detectable limit of the assay was determined as the highest dilution (1:320) of positive serum. No cross-reaction of the antibodies with other related canine or feline pathogens was observed. The DFICT can be stored for 12 months at 4°C or 6 months with no loss of sensitivity or specificity. A high degree of consistency was observed between the DFICT and the standard ELISA kit, supporting the reliability of the novel test strip. The introduction of a liquid gold nanoparticle conjugate reagent provides this method with several attractive characteristics, such as ease of manufacture, low sample volume requirements, high selectivity and high efficiency. This method opens a novel pathway for rapid diagnostic screening and field analysis.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China. Electronic address: jiangweijw99@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Qiufeng
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Peter
authors.initials: P
authors.lastname: Chun
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Kailing
authors.initials: K
authors.lastname: Yao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China.
authors.forename: Xiangan
authors.initials: X
authors.lastname: Han
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China.
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China.
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: liuyongjie@njau.edu.cn.
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences. No. 518, Ziyue Road, Minhang District, Shanghai 200241, China. Electronic address: wangquan@shvri.ac.cn.
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry; D002371:Cat Diseases / Q000097:blood / Q000175:diagnosis*; D002415:Cats / Q000469:parasitology; D002846:Chromatography, Affinity / Q000295:instrumentation*; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis*; D004285:Dogs / Q000469:parasitology; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D055767:Immobilized Proteins / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011934:Reagent Strips / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000295:instrumentation; D013205:Staphylococcal Protein A / Q000737:chemistry; D014122:Toxoplasma / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000097:blood / Q000175:diagnosis*
chemical_list: D000953:Antigens, Protozoan; D055767:Immobilized Proteins; D011934:Reagent Strips; D013205:Staphylococcal Protein A; D006046:Gold
keywords: Dynamic flow immunochromatographic test; Liquid gold nanoparticle conjugate; SPA; Simple manufacture; Toxoplasma gondii