基于金纳米线构建电化学传感器间接检测碱性磷酸酶活性

在临床实践中，碱性磷酸酶（ALP）是最常检测的酶之一，已被广泛用作肝病、骨病、乳腺癌、前列腺癌以及糖尿病等多种疾病的重要检测指标.通过自组装方法在氧化铟锡（ITO）导电玻璃上制备金纳米线（AuNWs），利用4-巯基苯甲酸（4-MBA）修饰AuNWs，对其进行改性，与铜离子（Cu²⁺）螯合形成Cu²⁺-AuNWs/ITO电极.在ALP活性检测中，电解液中的焦磷酸根阴离子（PPi）与电极表面Cu²⁺结合，湮灭了Cu²⁺的电化学信号.ALP的加入使底物PPi水解并释放出Cu²⁺，电化学信号增加.构建的Cu²⁺-AuNWs/ITO电极对ALP活性检测范围为60~180 U·L^-1，且抗干扰性能良好.

Indirect detection of alkaline phosphatase activity by electrochemical sensor based on gold nanowires

In the clinical practice, alkaline phosphatase (ALP) is one of the most frequently detected enzymes. It has been used as an important indicator of liver disease, bone disease, breast cancer, prostate cancer, diabetes, and other diseases. In this report, gold nanowires(AuNWs) were firstly prepared on indium tin oxide(ITO) conductive glass by self-assembly method. Then, AuNWs were modified by 4-mercaptobenzoic acid (4-MBA) and chelated with copper ions(Cu²⁺) to form the Cu²⁺-AuNWs/ITO electrode. In the detection of ALP activity, pyrophosphate anion(PPi) in the electrolyte combines with copper ions on the electrode surface to annihilate the electrochemical signal of copper ions. However, the addition of ALP hydrolyzes the substrate PPi and releases copper ions, which increases the electrochemical signal. The as-constructed Cu²⁺-AuNWs/ITO electrode can detect ALP activity in the range of 60~180 U·L^-1 with the high anti-interference performance.