摘要
利用溶胶凝胶法,将正硅酸乙酯在HCl存在下水解形成的硅溶胶和黄曲霉毒素B1抗体的混合液涂于玻碳电极表面,制备非标记型电化学阻抗免疫传感器。以[Fe(CN)6]3-/4-的磷酸盐缓冲溶液为测试底液,分别研究传感器的循环伏安和交流阻抗行为。实验表明,电极因免疫反应所形成的复合物阻碍了[Fe(CN)6]3-/4-在电极表面的扩散,其氧化还原峰电流明显减小,电子转移阻抗随黄曲霉毒素浓度增加而线性增大。当介质pH=6.5和孵育时间为20 min时,免疫前后传感器的电子转移阻抗变化值最大。在此最佳条件下,传感器电子转移阻抗对黄曲霉毒素响应的线性范围为1.0～10μg/L;检出限为0.1μg/L(S/N=3)。此方法具有高的灵敏度和稳定性,可应用于食品中黄曲霉毒素的测定。
In the presence of hydrochloric acid,tetraethoxysilicane was hydrolyzed and formed silica sol.Non-labeled immunosensor was fabricated by droping the mixture solution of the silica sol and antibody of aflatoxin B1 on the surface of glassy carbon electrode.In this work,a Fe（CN）6^3-/4- phosphate buffer solution was employed as base solution for investigating cyclic voltammetry（CV） and electrochemical impedance spectroscopic（EIS） performances of the sensor,respectively.The experimental results t indicated that because of the complex formed by the immunoreaction hindered the diffusion of Fe（CN）6^3-/4- on the electrode surface,the redox peak current of the immunosensor in CV obviously decreased,and its electron transfer impedance linearly increased with increasing the concentration of aflantoxin B_1（AFB）.When the medium acidit and incubation time were pH 6.5 and 20 min,respectively,the biggest electron transfer impedance changed value before and after the immunoreaction was obtained.Under the optimal conditions,a linear range to concentration of aflatoxin B1 was 1-10 μg/L with a detection limit of 0.1 μg/L（S/N=3）.Proposed method is of high sensitivity and stability,it has been successfully applied to determine AFB1 in maize,rice and peanut.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2010年第2期245-248,共4页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金资助(Nos.20771045
20676052
20806033)
国家高技术计划"863"项目(No.2007AA10Z428)
江南大学食品科学技术国家重点实验室开放引进课题(No.SKLF-G-2060204)资助
关键词
黄曲霉毒素
免疫传感器
交流阻抗
溶胶凝胶
Aflatoxin B1 Ιmmunosensor Εlectrochemical impedance spectroscopy Sol-gel
