title: Preparation of a visual protein chip for detection of IgG against Treponema pallidum.
abstract: A rapid, visual protein chip method for the detection of IgG against Treponema pallidum was developed using Staphylococcus protein A-modified gold nanoparticles. After recombinant T. pallidum antigen Tpp47 was arrayed on aldehyde-coated slides, qualitative and semiquantitative assay results were obtained from the hybridization signal and the subsequent gray stain values. The Tpp47-specific serum antibody was bound to immobilized Tpp47 antigen on the functionalized glass slides. The Staphylococcus protein A-modified gold nanoparticle probe exclusively recognized anti-Tpp47 IgG. The "sandwich" format hybridization signal was then amplified with silver staining, a high sensitivity visual detection technique. It took 3.5 h to prepare the detection protein chip, but only 20 min for real sample detection. The lowest titer of detectable antibody for this method was 1:128, which correlates to approx 1 ng/mL. Furthermore, the results can only be seen unaided, which drastically reduces the cost of detection, but can also be kept for a long time. The data also confirmed the proposed method's specificity, sensitivity, and convenience. As a result, the method could be applied as an alternative diagnostic tool in the clinical diagnosis of T. pallidum.
authors.affiliation: College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China. wangyefu@hotmail.com
authors.forename: Yefu
authors.initials: Y
authors.lastname: Wang
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Gao
authors.forename: Huaquan
authors.initials: H
authors.lastname: Wang
authors.forename: Yihong
authors.initials: Y
authors.lastname: Luo
mesh_terms: D000918:Antibody Specificity; D002352:Carrier Proteins / Q000276:immunology; D003102:Colloids / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology*; D008074:Lipoproteins / Q000276:immunology; D046529:Microscopy, Electron, Transmission; D040081:Protein Array Analysis / Q000379:methods*; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis; D014210:Treponema pallidum / Q000276:immunology*
chemical_list: C090573:47-kDa immunogen, Treponema pallidum; D002352:Carrier Proteins; D003102:Colloids; D007074:Immunoglobulin G; D008074:Lipoproteins; D006046:Gold