Electrochemical Biosensors Based on ZnO Nanostructures to Measure Intracellular Metal Ions and Glucose
- *Corresponding Author:
- Muhammad H. Asif
Materials Research, Department of Physics
COMSATS institute of Information Technology- Lahore-54000, Pakistan
E-mail: [email protected], [email protected]
Received date: July 01, 2011; Accepted date: September 26, 2011; Published date: September 30, 2011
Citation: Asif MH, Elinder F, Willander M (2011) Electrochemical Biosensors Based on ZnO Nanostructures to Measure Intracellular Metal Ions and Glucose. J Anal Bioanal Tech S7:003. doi: 10.4172/2155-9872.S7-003
Copyright: © 2011 Asif MH, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Zinc oxide (ZnO) nanostructures have attracted much interest for intracellular electrochemical measurements because of its large surface area, and its biocompatible properties. To design intracellular biosensors for metal ions and glucose, we grew ZnO nanorods on the tip of borosilicate glass capillaries (0.7µm in diameter) and characterized the nano-scale structure with field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The ZnO nanorods were functionalized accordingly for intracellular free metal ions or glucose measurements. Selectivity was achieved by using a metal-ion selective plastic membrane or glucose oxidase enzyme for glucose measurements. These functionalized ZnO nanorods showed high sensitivity and good biocompatibility for intracellular environments. Human adipocytes and frog oocytes were used for determinations of intracellular free metal ions and glucose concentrations. In this review, we discuss the simple and direct approach for intracellular measurements using ZnO nanostructure-based potentiometric biosensors for clinical and nonclinical applications. The performance of ZnO nanostructure-based intracellular sensor can be improved through engineering of morphology, effective surface area, functionality, and adsorption/desorption capability. This study paves the way to find applications in biomedicine by using this simple and miniaturized biosensing device.