基于离子液体-石墨烯-二茂铁的高灵敏电化学免疫传感器检测CEA

研究了在PBS缓冲介质中,一种检测癌胚抗原的新型免标记免疫电化学传感器的制备,将石墨烯、二茂铁的高效催化及壳聚糖的优良生物相容性和成膜性、离子液体的导电性等优势充分结合构建了电化学免疫传感器。通过循环伏安法及交流阻抗对修饰的电极进行表征,在最优条件下,癌胚抗原的质量浓度在0.2～50.0 ng/mL的范围内与差分脉冲伏安法峰电流呈良好的线性关系,回归方程为Δi=0.38-1.31ρ,相关系数分别为0.9967,检测限为0.06 ng/mL,该传感器可用于人血清样品的测定。

Highly sensitive CEA electrochemical immunosensor based on ionic liquid-graphene-ferrocene

Carcinoembryonic antigen(CEA) is an acknowledged tumor marker,therefore,it is valuable for determination of CEA in clinical diagnosis.A novel label-free electrochemical immunosensor for the detection of CEA has been developed by immobilizing anti-CEA on a glassy carbon electrode modified with composites made up of graphene sheets of good electrical conductivity,ferrocene of highly effective catalysis,chitosan of biocompatibility and ionic liquid of good electrical conductivity.The modification procedure was characterized by cyclic voltammetry and electrochemical impedance.The detection is based on the peak current change of the modified electrode before and after the antigen-antibody reaction.Under optimal condition,a linear relationship between the stripping response and the CEA concentration in the range from 0.2 to 50.0 ng/mL was obtained using an electrochemical technique,the linear regression equation is Δi=0.38-1.31ρ,the correlation coefficient is 0.9967,and the detection limit is 0.06 ng/mL.The sensor has good reproducibility,selectivity and stability,and it has been applied to the determination of human serum with satisfactory results.