Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , China.
ACS Appl Mater Interfaces. 2019 Jan 23;11(3):3474-3481. doi: 10.1021/acsami.8b18887. Epub 2019 Jan 10.
A simple magnetic electrochemical aptasensor was established for the detection of prostatic specific antigen (PSA). Ag/CdO nanoparticles (NPs) were fabricated and exhibited strong electroreduction peaks at -1.07 V, attributing to the electron transfer from Cd to Cd and the superior electron transportation of Ag. Aptamer-modified Ag/CdO NPs were assembled on the surface of superparamagnetic FeO/graphene oxide nanosheets (GO/FeO NSs) through the hydrophobic and π-π stacking interaction of aptamers and GO NSs. These assemblies possessed superior electroactive properties, efficient electron transfer, and superparamagnetic response and could serve as sensing units for PSA detection with the aid of a magnetic electrode. With increasing concentrations of PSA, the high affinity of aptamers to PSA enabled the dissociation of Ag/CdO NPs from GO/FeO NSs, decreasing the intensity of electroreduction peaks. The Ag/CdO NP-engineered magnetic electrochemical aptasensor achieved sensitive and accurate detection of PSA in the range of 50 pg/mL to 50 ng/mL. The limit of detection (LOD) was as low as 28 pg/mL. This developed protocol can be extended to a large set of strong electroactive labels for reliable tumor biomarker detection with high sensitivity and specificity.
建立了一种用于检测前列腺特异性抗原（PSA）的简单的磁性电化学适体传感器。制备了 Ag/CdO 纳米颗粒（NPs），并在-1.07 V 处表现出强的电还原峰，这归因于 Cd 到 Cd 的电子转移和 Ag 的优异电子输运能力。通过适体和 GO NSs 的疏水和π-π堆积相互作用，将修饰有适体的 Ag/CdO NPs 组装在超顺磁性 FeO/氧化石墨烯纳米片（GO/FeO NSs）的表面上。这些组装体具有优异的电活性、有效的电子转移和超顺磁性响应，并且可以在磁性电极的辅助下用作 PSA 检测的传感单元。随着 PSA 浓度的增加，适体与 PSA 的高亲和力使得 Ag/CdO NPs 从 GO/FeO NSs 上解离，从而降低了电还原峰的强度。Ag/CdO NP 工程化的磁性电化学适体传感器在 50 pg/mL 至 50 ng/mL 的范围内实现了对 PSA 的灵敏和准确检测。检测限（LOD）低至 28 pg/mL。该开发方案可以扩展到一组大型强电活性标签，用于高灵敏度和特异性的可靠肿瘤生物标志物检测。
