A disposable tear glucose biosensor - Part 3: Assessment of enzymatic specificity

Kenneth Lan, Kenyon McAferty, Pankti Shah, Erica Lieberman, Dharmendra R. Patel, Curtiss B. Cook, Jeffrey LaBelle

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Background: A concept for a tear glucose sensor based on amperometric measurement of enzymatic oxidation of glucose was previously presented, using glucose dehydrogenase flavin adenine dinucleotide (GDH-FAD) as the enzyme. Glucose dehydrogenase flavin adenine dinucleotide is further characterized in this article and evaluated for suitability in glucose-sensing applications in purified tear-like saline, with specific attention to the efect of interfering substances only. These interferents are specifically saccharides that could interact with the enzymatic activity seen in the sensor's performance. Methods: Bench top amperometric glucose assays were performed using an assay solution of GDH-FAD and ferricyanide redox mediator with samples of glucose, mannose, lactose, maltose, galactose, fructose, sucrose, and xylose at varying concentrations to evaluate specificity, linear dynamic range, signal size, and signal-to-noise ratio. A comparison study was done by substituting an equivalent activity unit concentration of glucose oxidase (GOx) for GDH-FAD. Results: Glucose dehydrogenase flavin adenine dinucleotide was found to be more sensitive than GOx, producing larger oxidation currents than GOx on an identical glucose concentration gradient, and GDH-FAD exhibited larger slope response (-5.65 × 10-7 versus -3.11 × 10-7 A/mM), signal-to-noise ratio (18.04 versus 2.62), and linear dynamic range (0-30 versus 0-10 mM), and lower background signal (-7.12 versus -261.63 nA) than GOx under the same assay conditions. GDH-FAD responds equally to glucose and xylose but is otherwise specific for glucose. Conclusion: Glucose dehydrogenase flavin adenine dinucleotide compares favorably with GOx in many sensor-relevant attributes and may enable measurement of glucose concentrations both higher and lower than those measurable by GOx. GDH-FAD is a viable enzyme to use in the proposed amperometric tear glucose sensor system and perhaps also in detecting extreme hypoglycemia or hyperglycemia in blood.

Original languageEnglish (US)
Pages (from-to)1108-1115
Number of pages8
JournalJournal of Diabetes Science and Technology
Issue number5
StatePublished - Sep 2011


  • Biosensor
  • Diabetes mellitus
  • Glucose dehydrogenase flavin adenine dinucleotide
  • Tear glucose monitoring

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism
  • Bioengineering
  • Biomedical Engineering


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