Laboratory of Bioanalysis, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran. MEMS & NEMS Lab, Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran. Department of Nanotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran.
Nanotechnology. 2018 Jun 29;29(26):265102. doi: 10.1088/1361-6528/aabca3. Epub 2018 Apr 9.
Immunosensors based on interdigitated electrodes (IDEs), have recently demonstrated significant improvements in the sensitivity of capacitance detection. Herein, a novel type of highly sensitive, compact and portable immunosensor based on a gold interdigital capacitor has been designed and developed for the rapid detection of hepatitis B surface antigen (HBsAg). To improve the efficiency of antibody immobilization and time-saving, a self-assembled monolayer (SAM) of 2-mercaptoethylamine film was coated on IDEs. Afterwards, carboxyl groups on primary antibodies were activated through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and were immobilized on amino-terminated SAM for better control of the oriented immobilization of antibodies on gold IDEs. In addition, gold nanoparticles conjugated with a secondary antibody were used to enhance the sensitivity. Under optimal conditions, the immunosensor exhibited the sensitivity of 0.22 nF.pg ml, the linear range from 5 pg ml to 1 ng ml and the detection limit of 1.34 pg ml, at a signal-to-noise ratio of 3.
基于叉指电极（IDEs）的免疫传感器最近在电容检测的灵敏度方面取得了显著的提高。本文设计并开发了一种新型的基于金叉指电容器的高灵敏度、紧凑且便携的免疫传感器，用于快速检测乙型肝炎表面抗原（HBsAg）。为了提高抗体固定化的效率和节省时间，在 IDE 上涂覆了 2-巯基乙胺薄膜的自组装单分子层（SAM）。随后，通过 1-乙基-3-（3-二甲基氨基丙基）碳二亚胺将抗体上的羧基基团激活，并固定在氨基末端的 SAM 上，以更好地控制抗体在金 IDE 上的定向固定。此外，还使用与二级抗体偶联的金纳米粒子来提高灵敏度。在最佳条件下，该免疫传感器的灵敏度为 0.22 nF.pg ml，线性范围为 5 pg ml 至 1 ng ml，检测限为 1.34 pg ml，信噪比为 3。
