Simultaneous detection of uric acid and glucose on a dual-enzyme chip using scanning electrochemical microscopy/scanning chemiluminescence microscopy

Shigenobu Kasai, Yu Hirano, Naomi Motochi, Hitoshi Shiku, Matsuhiko Nishizawa, Tomokazu Matsue

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Scanning electrochemical microscopy (SECM) and scanning chemiluminescence microscopy (SCLM) were used for imaging an enzyme chip with spatially-addressed spots for glucose oxidase (GOD) and uricase microspots. For the SECM imaging, hydrogen peroxide generated from the GOD and/or uricase spots was directly oxidized at the tip microelectrode in a solution containing glucose and/or uric acid (electrochemical (EC) detection). For the SCLM imaging, a tapered glass capillary (i.d. of 1∼2μm) filled with luminol and horseradish peroxidase (HRP) was used as the scanning probe for generating the chemiluminescence (CL). The inner solution was injected from the capillary tip at 78pls-1 while scanning above the enzyme-immobilized chip. The CL generated when the capillary tip was scanned above the enzyme spots was detected using a photon-counter (CL detection). Two-dimensional mapping of the oxidation current and photon-counting intensity against the tip position affords images of which their contrast reflects the activity of the immobilized GOD and uricase. For both the EC and CL detections, the signal responses were plotted as a function of the glucose and uric acid concentrations in solution. The sensitivities for the EC and CL detection were found to be comparable.

Original languageEnglish
Pages (from-to)263-270
Number of pages8
JournalAnalytica Chimica Acta
Volume458
Issue number2
DOIs
Publication statusPublished - 2002 May 6

Keywords

  • Dual-enzyme chip
  • Electrochemical
  • Glucose oxidase (GOD)
  • Microscopy
  • Scanning
  • Scanning chemiluminescence microscopy
  • Uricase

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Environmental Chemistry
  • Spectroscopy

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