College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China.
Sensors (Basel). 2020 Jul 16;20(14):3956. doi: 10.3390/s20143956.
A simple and low-cost electrochemical sensor based on multimodified screen-printed electrodes (SPEs) was successfully synthesized for the sensitive detection of β-lactoglobulin (β-Lg). The surface treatment of SPEs was accomplished by a simple drip coating method using polyethyleneimine (PEI), reduced graphene oxide (rGO), and gold nanoclusters (AuNCs), and the treated SPEs showed excellent electrical conductivity. The modified SPEs were then characterized with UV-Vis, SEM, TEM, and FTIR to analyze the morphology and composition of the AuNCs and the rGO. An anti-β-Lg antibody was then immobilized on the composite material obtained by modifying rGO with PEI and AuNCs (PEI-rGO-AuNCs), leading to the remarkable reduction in conductivity of the SPEs due to the reaction between antigen and antibody. The sensor obtained using this novel approach enabled a limit of detection (LOD) of 0.08 ng/mL and a detection range from 0.01 to 100 ng/mL for β-Lg. Furthermore, pure milk samples from four milk brands were measured using electrochemical sensors, and the results were in excellent agreement with those from commercial enzyme-linked immunosorbent assay (ELISA) methods.
基于多修饰丝网印刷电极（SPEs）的简单且低成本电化学传感器成功合成，用于灵敏检测β-乳球蛋白（β-Lg）。通过使用聚乙烯亚胺（PEI）、还原氧化石墨烯（rGO）和金纳米簇（AuNCs）的简单滴涂方法完成 SPE 的表面处理，处理后的 SPE 表现出优异的导电性。然后使用 UV-Vis、SEM、TEM 和 FTIR 对修饰后的 SPE 进行了表征，以分析 AuNCs 和 rGO 的形态和组成。然后将抗β-Lg 抗体固定在通过用 PEI 和 AuNCs 修饰 rGO 获得的复合材料上（PEI-rGO-AuNCs），由于抗原和抗体之间的反应，导致 SPE 的电导率显著降低。使用这种新方法获得的传感器可实现 0.08 ng/mL 的检测限（LOD）和 0.01 至 100 ng/mL 的检测范围β-Lg。此外，使用电化学传感器测量了来自四个牛奶品牌的纯牛奶样品，结果与商业酶联免疫吸附测定（ELISA）方法非常吻合。
