Label-free immunoassay for porcine circovirus type 2 based on excessively tilted fiber grating modified with staphylococcal protein A

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• 作者：Binbin Luo^a ; ^c ; ^d ; Shengxi Wu^b ; ^{sxwu2004@cqut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Wengen Zou^a ; Zhonghao Zhang^b ; Mingfu Zhao^a ; Shenghui Shi^a ; Yong Liu^c ; Xiangfeng Xi^e ; Zheng Zeng^f ; Wangwang Liang^f ; Zhijun Yan^d ; Lin Zhang^d
• 关键词：Label-free immunoassay ; Excessively tilted fiber grating (Ex-TFG) ; Porcine circovirus type 2 (PCV2) ; Staphylococcal protein A (SPA) ; Monoclonal antibody (MAb)
• 刊名：Biosensors and Bioelectronics
• 出版年：2016
• 出版时间：15 December 2016
• 年：2016
• 卷：86
• 期：Complete
• 页码：1054-1060
• 全文大小：1495 K

文摘

Using excessively tilted fiber grating (Ex-TFG) inscribed in standard single mode fiber, we developed a novel label-free immunoassay for specific detection of porcine circovirus type 2 (PCV2), which is a minim animal virus. Staphylococcal protein A (SPA) was used to modify the silanized fiber surface thus forming a SPA layer, which would greatly enhance the proportion of anti-PCV2 monoclonal antibody (MAb) bioactivity, thus improving the effectiveness of specific adsorption and binding events between anti-PCV2 MAbs and PCV2 antigens. Immunoassay experiments were carried out by monitoring the resonance wavelength shift of the proposed sensor under different PCV2 titer levels. Anti-PCV2 MAbs were thoroughly dissociated from the SPA layer by treatment with urea, and recombined to the SPA layer on the sensor surface for repeated immunoassay of PCV2. The specificity of the immunosensor was inspected by detecting porcine reproductive and respiratory syndrome virus (PRRSV) first, and PCV2 subsequently. The results showed a limit of detection (LOD) for the PCV2 immunosensor of ~9.371TCID₅₀/mL, for a saturation value of ~4.801×10³TCID₅₀/mL, with good repeatability and excellent specificity.