使用CoAl层状双氢氧化物（CoAl-LDH）和羧基功能化多壁碳纳米管（MWCNTs-COOH）的新型复合材料和二茂铁羧酸，开发了一种用于超灵敏测定癌症抗原的新型无标记电化学免疫传感器（CA724） (Fc-COOH) 作为信号标签。 MWCNTs-COOH/Fc-COOH@CoAl-LDH复合材料是通过一种方便、简单的一步超声方法以及包括扫描电子显微镜（SEM）、透射电子显微镜（TEM）、TEM-Mapping、应用傅里叶变换红外（FT-IR）、X射线衍射（XRD）和X射线光电子能谱（XPS）研究了尺寸和形态特征。由于其较大的比表面积和多层结构，CoAl-LDH可以通过后掺杂嵌入大量信号探针，实现内部参考信号Fc的放大。此外，MWCNTs-COOH较高的电导率弥补了CoAl-LDH的不足，有效增强了电化学信号物质的电子传递效率。确定最佳实验条件为Fc-COOH用量2.5 mmol、浓度4.0 mg/mL、pH 6.0、孵育时间40 min、孵育温度37 ℃。在最佳条件下，所制作的传感器在涵盖生理浓度（0.001至100 U/mL）的宽动态范围内表现出线性，检测限（LOD）为0.03962 mU/mL，校准方程为△I = 7.76363 log10CCA724 40.50351 (R2 = 0.99674)。该传感器成功检测人血清中的痕量 CA724，回收率范围为 100.52%-102.30%，证明了 MWCNTs-COOH/Fc-COOH@CoAl-LDH 的协同作用，作为电化学传感临床检测的有前途的平台。其他疾病标志物。版权所有 © 2024。由 Elsevier B.V. 出版

A novel label-free electrochemical immunosensor for the ultrasensitive determination of cancer antigen (CA724) was developed using a novel composite of CoAl layered double hydroxides (CoAl-LDH) and carboxyl-functionalized multiwall carbon nanotubes (MWCNTs-COOH) as platform and ferrocenecarboxylic acid (Fc-COOH) as signal label. The MWCNTs-COOH/Fc-COOH@CoAl-LDH composite was prepared by a convenient and simple one-step ultrasonic method, and various characterization techniques consisting of scanning electron microscopy (SEM), transimission electronic microscopy (TEM), TEM-Mapping, fourier transform infrared (FT-IR), X-ray diffraction (XRD) and X-ray photoelectronic energy spectrum (XPS) were applied to study the size and morphological features. Due to its large specific surface area and multilayer structure, the CoAl-LDH can be post-doped to embed a large amount of signal probe to realize the amplification of the internal reference signal Fc. In addition, the higher conductivity of MWCNTs-COOH compensates for the deficiency of CoAl-LDH, which effectively strengthened the electron transfer efficiency of electrochemical signaling substances. The optimal experimental conditions were detected to be 2.5 mmol of Fc-COOH, 4.0 mg/mL of concentration, pH 6.0, incubation time of 40 min, and incubation temperature of 37 ℃. Under optimal conditions, the fabricated sensor exhibits linearity in a wide dynamic range covering the physiological concentration, from 0.001 to 100 U/mL and the limit of detection (LOD) was 0.03962 mU/mL, the calibration equation is stated as △I = 7.76363 log10CCA724 + 40.50351 (R2 = 0.99674). The sensor is successfully detects trace levels of CA724 in human serum with excellent recovery rates ranging from 100.52 %-102.30 %, proving the synergy of MWCNTs-COOH/Fc-COOH@CoAl-LDH as a promising platform for electrochemical sensing for clinical detection of other disease markers.Copyright © 2024. Published by Elsevier B.V.