The Conductive and Electroactive Polymer Research Unit, The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330, Thailand; Center of Excellence on Petrochemical and Materials Technology (PETROMAT), Chulalongkorn University Research Building, Bangkok 10330, Thailand.
Medical Oncology Unit, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Department of Medicine, Faculty of Medicine, Chulalongkorn University, Thailand.
Bioelectrochemistry. 2023 Aug;152:108446. doi: 10.1016/j.bioelechem.2023.108446. Epub 2023 Apr 13.
Carcinoembryonic antigen (CEA) is a cancer marker used for monitoring cancer treatment. Herein, a label-free electrochemical immunosensor for determining CEA concentration composed of the thiolated chitosan (tCHI) and the doped poly(N-methylaniline) (dPNMA) is proposed. The tCHI served as a support matrix for the immobilization of CEA antibodies (anti-CEA) and was prepared by using 11-mercaptoundecanoic acid (MUA) as a grafting agent on chitosan (CHI). The excellent electrical conductivity of the dPNMA was utilized as an electron transfer layer for the proposed immunosensor. The successful preparation of the tCHI was confirmed by the attenuated-total reflection Fourier transform spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to illustrate the performance of the proposed immunosensor. The determination of CEA concentration was relied on the decrease in the DPV current response with increasing CEA concentration from the creation of the antigen-antibody immunocomplex. The proposed immunosensor demonstrated a broad concentration range of 0.01 to 30 ng mL with a low limit of detection (LOD) of 0.01 ng mL. In addition, the present sensor exhibited excellent selectivity, reproducibility, and long-term stability, suggesting its potential use to determine CEA in clinical immunoassay.
癌胚抗原（CEA）是一种用于监测癌症治疗的肿瘤标志物。在此，提出了一种由巯基化壳聚糖（tCHI）和掺杂聚 N-甲基苯胺（dPNMA）组成的用于测定 CEA 浓度的无标记电化学免疫传感器。tCHI 用作固定 CEA 抗体（抗 CEA）的支撑基质，并用 11-巯基十一酸（MUA）作为接枝剂在壳聚糖（CHI）上制备。dPNMA 的优异导电性被用作所提出的免疫传感器的电子转移层。tCHI 的成功制备通过衰减全反射傅里叶变换光谱（ATR-FTIR）、X 射线光电子能谱（XPS）和扫描电子显微镜（SEM）得到证实。循环伏安法（CV）、差分脉冲伏安法（DPV）和电化学阻抗谱（EIS）用于说明所提出的免疫传感器的性能。CEA 浓度的测定依赖于随着抗原-抗体免疫复合物的形成，DPV 电流响应随 CEA 浓度的增加而降低。所提出的免疫传感器表现出 0.01 至 30ngmL 的宽浓度范围和 0.01ngmL 的低检测限（LOD）。此外，该传感器表现出优异的选择性、重现性和长期稳定性，表明其在临床免疫分析中测定 CEA 的潜在用途。
