Development of a diamine biosensor

Clarke X. Xu, Sayed A.M. Marzouk, Vasile V. Cosofret, Richard P. Buck, Michael R. Neuman, Robert H. Sprinkle

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


An amperometric diamine sensor is developed for clinical applications in diagnosis of bacterial vaginosis (BV). The sensor is based on crosslinked putrescine oxidase (PUO) which catalyzes the conversion of diamines (mainly putrescine and cadaverine) to products including hydrogen peroxide. The hydrogen peroxide is detected anodically at platinum electrode polarized at 0.5 V versus Ag/AgCl. Platinum-plated gold electrodes used as a substrate for the sensor construction, are batch-fabricated on a flexible polyimide foil (Kapton®, DuPont). A three-electrode cell configuration is used in all amperometric measurements. The sensor construction is based on three layers: an inner layer to reject the interference effect of oxidizable molecules, an outer diffusion controlling layer, and in addition, an enzyme middle layer. The enzyme layer was immobilized by crosslinking PUO with bovine serum albumin (BSA) using glutaraldehyde (GA). An optimization study of the enzyme solution composition was carried out. With the optimized enzyme layer, the biosensor showed a very high sensitivity and fast response time of ca. 20 s. The sensor has a linear dynamic range from (0.5-300 μM) for putrescine that covers the expected biological levels of the analyte. Details on sensor fabrication and characterization are given in the present work.

Original languageEnglish
Pages (from-to)1625-1632
Number of pages8
Issue number9
Publication statusPublished - Sept 1997
Externally publishedYes


  • Bacterial vaginosis
  • Biosensor
  • Diamines
  • Putrescine oxidase

ASJC Scopus subject areas

  • Analytical Chemistry


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