基于自组装单分子层平台的无介体胆固醇生物传感器。

Mediator free cholesterol biosensor based on self-assembled monolayer platform.

机构信息

Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory (CSIR), Dr K. S. Krishnan Marg, New Delhi, 110012, India.

出版信息

Analyst. 2012 Feb 7;137(3):747-53. doi: 10.1039/c1an15196g. Epub 2011 Dec 1.

DOI:10.1039/c1an15196g

PMID:22132413

Abstract

Self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) has been investigated for immobilization of bi-enzymes (ChOx and ChEt) towards development of enzyme biosensors for detection of free and total cholesterol. This enzyme immobilized SAM surface has been characterized by scanning electron microscopy and electrochemical measurements. The results of electrochemical response studies reveal fast enzymatic reaction in phosphate buffer saline solution without using any artificial mediator. This may be attributed to the molecular wire type behavior of short 4-ATP molecule that promotes electron transfer between enzyme and the electrode surface due to its conjugated structure. Interference free estimation of free and total cholesterol has been realized at low operating potential of 0.33 V with range of detection as 25 to 400 mg dl(-1), sensitivity of 542.3 nA mM(-1) (for ChOx/4-ATP/Au) and 886.6 nA mM(-1) (for ChEt-ChOx/4-ATP/Au) with a response time of 20 s at pH 7.4.

摘要

4-巯基苯胺（4-ATP）的自组装单分子层已被研究用于固定双酶（ChOx 和 ChEt），以开发用于检测游离和总胆固醇的酶生物传感器。通过扫描电子显微镜和电化学测量对这种酶固定的 SAM 表面进行了表征。电化学响应研究的结果表明，在不使用任何人工介质的情况下，在磷酸盐缓冲盐溶液中进行快速酶反应。这可能归因于短 4-ATP 分子的分子线类型行为，由于其共轭结构，促进了酶和电极表面之间的电子转移。在低工作电位 0.33 V 下，可以实现对游离和总胆固醇的无干扰估计，检测范围为 25 至 400 mg dl(-1)，ChOx/4-ATP/Au 的灵敏度为 542.3 nA mM(-1)，ChEt-ChOx/4-ATP/Au 的灵敏度为 886.6 nA mM(-1)，响应时间为 20 s，pH 值为 7.4。