In vitro glucose concentration measurement by a reusable enzymatic glucose sensor and a highly stable circular heterodyne polarimeter.

A reliable glucose concentration measurement system was proposed that consisted of a circular heterodyne polarimeter and a reusable enzymatic sensor. The circular heterodyne polarimeter was constructed using a highly stable circular heterodyne light source and a compact alignment-free apparatus that provided phase stability of less than 1° within 20 min. The reusable enzymatic glucose sensor can be reused more than 100 times and retain 90% of its initial performance under optimum storage conditions within a month. The proposed method can be used to determine glucose concentrations in aqueous solutions and human serum. The optimum resolution of the proposed method was approximately 0.88 mg/dl for the glucose solution and 0.68 mg/dl for the serum-based sample.