LSI-based amperometric sensor for bio-imaging and multi-point biosensing

Lab Chip. 2012 Sep 21;12(18):3481-90. doi: 10.1039/c2lc40323d. Epub 2012 Jul 30.

Abstract

We have developed an LSI-based amperometric sensor called "Bio-LSI" with 400 measurement points as a platform for electrochemical bio-imaging and multi-point biosensing. The system is comprised of a 10.4 mm × 10.4 mm CMOS sensor chip with 20 × 20 unit cells, an external circuit box, a control unit for data acquisition, and a DC power box. Each unit cell of the chip contains an operational amplifier with a switched-capacitor type I-V converter for in-pixel signal amplification. We successfully realized a wide dynamic range from ±1 pA to ±100 nA with a well-organized circuit design and operating software. In particular, in-pixel signal amplification and an original program to control the signal read-out contribute to the lower detection limit and wide detection range of Bio-LSI. The spacial resolution is 250 μm and the temporal resolution is 18-125 ms/400 points, which depends on the desired current detection range. The coefficient of variance of the current for 400 points is within 5%. We also demonstrated the real-time imaging of a biological molecule using Bio-LSI. The LSI coated with an Os-HRP film was successfully applied to the monitoring of the changes of hydrogen peroxide concentration in a flow. The Os-HRP-coated LSI was spotted with glucose oxidase and used for bioelectrochemical imaging of the glucose oxidase (GOx)-catalyzed oxidation of glucose. Bio-LSI is a promising platform for a wide range of analytical fields, including diagnostics, environmental measurements and basic biochemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques*
  • Electrochemical Techniques / instrumentation
  • Electrochemical Techniques / methods*
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Glucose / analysis
  • Glucose Oxidase / chemistry
  • Glucose Oxidase / metabolism
  • Horseradish Peroxidase / chemistry
  • Horseradish Peroxidase / metabolism
  • Hydrogen Peroxide / chemistry
  • Oxidation-Reduction

Substances

  • Enzymes, Immobilized
  • Hydrogen Peroxide
  • Glucose Oxidase
  • Horseradish Peroxidase
  • Glucose