基于PSS/PAH包被的AuNRs免疫传感器用于CEA的测定

A Novel Immunosensor for the Detection of CEA Based on AuNRs Coated with PSS/PAH

通过聚苯乙烯磺酸钠（PSS）与聚丙烯氯化铵（PAH）以层层堆积（LBL）的形式包被到金纳米棒（AuNRs）的表面,从而替换AuNRs表面具有生物毒性的十六烷基三甲基溴化铵（CTAB）.将癌胚抗原（CEA）的抗体（Ab）交联到AuNRs的表面,研制出一种新的癌胚抗原（CEA）的检测方法.随着CEA与AuNRs表面的Ab发生特异性反应,使AuNRs发生自组装,从而导致其紫外可见吸收光谱发生变化.通过测量吸收光谱的变化可以实现CEA的定量检测.采用电化学交流阻抗法和循环伏安法考察了不同修饰层结合到AuNRs表面后的变化情况;考察了溶液pH、Ab与CEA的结合时间对响应的影响.在最优条件下,该传感器的检测范围为10～100 ng/mL,检测下限为3.3 ng/mL.

Gold nanorods （AuNRs） was coated with poly（styrene sulfonate）（PSS） and poyl（allylamine）hydrochloride（PAH）by layer-by-layer（LBL）deposition,replacing hexadecyl trimethyl ammonium bromide（CTAB）on the surface of AuNRs,which have a biological toxicity for biomolecule.Antibody of CEA was crosslinked on the surface of AuNRs to develop a novel method to detect CEA.A specific reaction between CEA and Ab caused AuNRs self-assembly which resulted in a change of UV-Vis absorption.The quantitative detection of CEA concentration can be realized through detecting the change of UV-Vis absorption.Different modify process on the surface of AuNRs were studied by electrochemical impedance and cyclic voltammetry.The effects of pH and reaction time were investigated.The results showed that the immunosensor exhibits good linear response to CEA in range of 10～100 ng/mL and the detection limit was 3.3 ng/mL.