title: A conductometric indium oxide semiconducting nanoparticle enzymatic biosensor array.
abstract: 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.
authors.affiliation: Department of Mechanical Engineering, University of Minnesota, 111 Church St. S.E., Minneapolis, MN 55455, USA. djlee@umn.edu
authors.forename: Dongjin
authors.initials: D
authors.lastname: Lee
authors.forename: Janet
authors.initials: J
authors.lastname: Ondrake
authors.forename: Tianhong
authors.initials: T
authors.lastname: Cui
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation* / Q000379:methods*; D004560:Electricity; D004566:Electrodes; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000378:metabolism*; D007204:Indium / Q000737:chemistry*; D008027:Light; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012542:Scattering, Radiation; D012666:Semiconductors; D013997:Time Factors
chemical_list: D007204:Indium; C047711:indium oxide; D005949:Glucose Oxidase; D005947:Glucose