Cholesterol biosensor based on N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane self-assembled monolayer

Anal Biochem. 2007 Apr 15;363(2):210-8. doi: 10.1016/j.ab.2007.01.029. Epub 2007 Jan 26.

Abstract

Cholesterol oxidase (ChOx) has been covalently immobilized onto two-dimensional self-assembled monolayer (SAM) of N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (AEAPTS) deposited on the indium-tin oxide (ITO) coated glass plates using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) chemistry. These ChO x/AEAPTS/ITO bioelectrodes are characterized using contact angle (CA) measurements, UV-visible spectroscopy, atomic force microscopy (AFM), electrochemical impedance technique, and Fourier transform infrared (FT-IR) technique. The covalently immobilized ChOx-modified AEAPTS bioelectrodes are used for the estimation of cholesterol in solution using UV-visible technique. These cholesterol sensing bioelectrodes show linearity as 50 to 500 mg/dl for cholesterol solution, detection limit as 25mg/dl, sensitivity as 4.499 x 10(-5) Abs (mg/dl)(-1), K(m) value as 58.137 mg/dl (1.5mM), apparent enzyme activity as 1.81 x 10(-3) U cm(-2), shelf life of approximately 10 weeks, and electrode reusability as 10 times.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Cholesterol / analysis*
  • Cholesterol / metabolism
  • Cholesterol Oxidase / chemistry
  • Cholesterol Oxidase / metabolism
  • Electrochemistry
  • Electrodes
  • Microscopy, Atomic Force
  • Models, Chemical
  • Molecular Structure
  • Reproducibility of Results
  • Silanes / chemistry*
  • Spectrophotometry, Ultraviolet

Substances

  • Silanes
  • Cholesterol
  • Cholesterol Oxidase
  • trimethoxysilane