摘要
依次电沉积氧化石墨烯、2,5二(2噻吩)-1-对苯甲酸吡咯和氯金酸于金电极表面,以EDC/NHS为活化剂,将黄曲霉毒素B_1(AFB_1)抗体共价连接在导电高分子膜上,最后滴涂1,3-二丁基咪唑六氟磷酸盐离子液体于上述修饰电极表面,制得AFB_1免疫传感器。以Fe(CN)_6^(3-/4-)的磷酸盐缓冲溶液(pH 7.0)为测试底液,采用循环伏安法和交流阻抗法考察此免疫传感器的电化学行为。研究表明:石墨烯和纳米金的引入明显提高了修饰层的电子转移速率,使电极的表观活性面积由裸金电极的0.1772 cm^2增加到0.2188 cm^2和0.2640 cm^2。当AFB_1浓度在3.2×10^(-15)～3.2×10^(-13)mol/L范围内,传感器的交流阻抗响应值与浓度呈线性关系,相关系数R^2=0.994,检出限为1.1×10^(-15)mol/L。传感器在4℃下保存20周以上,电化学响应保持基本不变。本方法的灵敏度和稳定性优于现有文献报道,并应用于花生样品中痕量AFB_1的测定。
To fabricate the aflatoxin B_1 immunosensor,graphene oxide,2,5-di-（2-thienyl）-l-pyrrole-l- （p-benzoic acid） and chloroauric acid were electrodeposited on the gold electrode surface in sequence. Then aflatoxin B_1（AFB_1） antibody was covalently connected to the conducting polymer film with 1- ethyl-（3-dimethyl-aminopropyl）-carbodimide/N-hydroxysuccimimide（EHC/NHS） as activator and 1,3-dibutyliminazolium hexafluorophosphate ionic liquid was finally coated on the modified electrode. The Fe（CN）_6^（3-/4-）phosphate buffer solution（pH 7.0） was employed as base solution for investigating electrochemical performances of the immunosensor by cyclic voltammetry and electrochemical impedance spectroscopy.Research revealed the introduction of graphene and gold nanocomposite obviously improved electron transfer rate of the modified layer,and the apparent electroactive surface areas of the electrode also increased up to 0.2188 cm^2 and 0.2640 cm^2 from 0.1772 cm^2 of bare gold electrode, respectively.When aflatoxin B_1 concentration is in the range of 3.2×10^（-15）—3.2×10^（-13） mol/L,the electron transfer impedance responses of the sensor will linearly increase.The correlation coefficient （R^2 ） and the detection limit were found to be 0.994 and 1.1×10^（15） mol/L.The electrochemical response of the immunosenor can keep almost constant after stored at 4℃for 20 weeks.Sensitivity and stability of the proposed method are better than those of other methods reported in literatures,it has been successfully applied to determination of trace AFB_1 in peanut samples.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期1635-1641,共7页
Chinese Journal of Analytical Chemistry
基金
国家科技支撑计划(No.2011BAK10B032)
国家自然科学基金(No.21176101)
浙江省自然科学基金(No.Y4100729)
江苏省“青蓝工程”资助项目
