A conductometric indium oxide semiconducting nanoparticle enzymatic biosensor array

Dongjin Lee, Janet Ondrake, Tianhong Cui

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


We report a conductometric nanoparticle biosensor array to address the significant variation of electrical property in nanomaterial biosensors due to the random network nature of nanoparticle thin-film. Indium oxide and silica nanoparticles (SNP) are assembled selectively on the multi-site channel area of the resistors using layer-by-layer self-assembly. To demonstrate enzymatic biosensing capability, glucose oxidase is immobilized on the SNP layer for glucose detection. The packaged sensor chip onto a ceramic pin grid array is tested using syringe pump driven feed and multi-channel I-V measurement system. It is successfully demonstrated that glucose is detected in many different sensing sites within a chip, leading to concentration dependent currents. The sensitivity has been found to be dependent on the channel length of the resistor, 4-12 nA/mM for channel lengths of 5-20 μm, while the apparent Michaelis-Menten constant is 20 mM. By using sensor array, analytical data could be obtained with a single step of sample solution feeding. This work sheds light on the applicability of the developed nanoparticle microsensor array to multi-analyte sensors, novel bioassay platforms, and sensing components in a lab-on-a-chip.

Original languageEnglish (US)
Pages (from-to)9300-9312
Number of pages13
Issue number10
StatePublished - Oct 2011


  • Biosensor array
  • Conductometric sensor
  • Glucose sensor
  • Microsensor array
  • Nanoparticle


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