Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Biosens Bioelectron. 2018 Dec 30;122:25-31. doi: 10.1016/j.bios.2018.09.034. Epub 2018 Sep 11.
In this study, a sensitive aptasensor based on three-dimensional reduced graphene oxide-modified gold nanoparticles (3D-rGO/AuNPs) was fabricated for the determination of arsenite (As(III)). The 3D-rGO/AuNPs was fully characterized with various techniques. The 5'-thiolate aptamer was first self-assembled on a glassy carbon electrode (GCE) that it's modified with 3D-rGO/AuNPs via Au-S covalent bonding. In the presence of As(III), the G-quadruplex interaction was formed between a single-stranded DNA and the target, which produced a hindrance for electron transfer. Consequently, the electrochemical impedance spectroscopy signals of a GCE modified with 3D-rGO/AuNPs was increased. In order to improve the response of the designing aptasensor, the effect of the various parameters was optimized. Under the optimal conditions, the aptasensor has an extraordinarily low detection limit of 1.4 × 10 ng mL toward As(III) with a dynamic range of 3.8 × 10 3.0 × 10 ng mL. The 3D-rGO/AuNPs aptasensor displayed superior selectivity and reproducibility with an acceptable recovery for determination of As(III) in real water samples.
在这项研究中，基于三维还原氧化石墨烯修饰的金纳米粒子（3D-rGO/AuNPs）构建了一种灵敏的适体传感器，用于测定亚砷酸盐（As(III)）。采用多种技术对 3D-rGO/AuNPs 进行了全面表征。5'-硫醇适体首先通过 Au-S 共价键自组装在经过 3D-rGO/AuNPs 修饰的玻碳电极（GCE）上。在存在 As(III) 的情况下，单链 DNA 与靶标之间形成 G-四链体相互作用，从而阻碍了电子转移。因此，经过 3D-rGO/AuNPs 修饰的 GCE 的电化学阻抗谱信号增加。为了提高设计适体传感器的响应，优化了各种参数的影响。在最佳条件下，该适体传感器对 As(III) 的检测限低至 1.4×10 ng mL，动态范围为 3.8×10 3.0×10 ng mL。3D-rGO/AuNPs 适体传感器具有优异的选择性和重现性，用于测定实际水样中的 As(III) 时具有可接受的回收率。
