Gold nanoparticles-coated magnetic microspheres as affinity matrix for detection of hemoglobin A1c in blood by microfluidic immunoassay

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• 作者：Shao-Peng Chen^a ; Xiao-Dong Yu^a ; Jing-Juan Xu ; ^a ; ^{xujj@nju.edu.cn"" rel=""nofollow} ; Hong-Yuan Chen^a
• 关键词：Hemoglobin A1c (HbA1c) ; Immunoassay ; Magnetic particles ; Microchip
• 刊名：Biosensors and Bioelectronics
• 出版年：2011
• 出版时间：15 August 2011
• 年：2011
• 卷：26
• 期：12
• 页码：4779-4784
• 全文大小：699 K

文摘

A novel microfluidic immunoassay system for specific detection of hemoglobin A1c (HbA1c) was developed based on a three-component shell/shell/core structured magnetic nanocomposite Au/chitosan/Fe₃O₄, which was synthesized with easy handling feature of Fe₃O₄ by magnet, high affinity for gold nanoparticles of chitosan and good immobilization ability for anti-human hemoglobin-A1c antibody (HbA1c mAb) of assembled colloidal gold nanoparticles. The resulting HbA1c mAb/Au/chitosan/Fe₃O₄ magnetic nanoparticles were then introduced into microfluidic devices coupled with a gold nanoband microelectrode as electrochemical detector. After that, three-step rapid immunoreactions were carried out in the sequence of HbA1c, anti-human hemoglobin antibodies (Hb mAb) and the secondary alkaline phosphatase (AP)-conjugated antibody within 20 min. The current response of 1-naphtol obtained from the reaction between the secondary AP-conjugated antibody and 1-naphthyl phosphate (1-NP) increased proportionally to the HbA1c concentration. Under optimized electrophoresis and detection conditions, HbA1c responded linearly in the concentration of 0.05–1.5 μg mL^−1, with the detection limit of 0.025 μg mL^−1. This system was successfully employed for detection of HbA1c in blood with good accuracy and renewable ability. The proposed method proved its potential use in clinical immunoassay of HbA1c.