A Disposable Tear Glucose Biosensor—Part 5: Improvements in Reagents and Tear Sampling Component

Abstract

A tear glucose (TG) sensor with an integrated tear sampler can provide a noninvasive method for calibrating the continuous TG contact lens and monitoring glucose. Expanding from previous work, an improved TG sensor that implements dried reagents, genetically modified glucose dehydrogenase (GDH), and a tear sampler was developed and compared against the TG sensor prepared with commercial GDH. It was found that neither sensor was affected by the tear interferents: ascorbic acid, acetaminophen, and uric acid. The sensor prepared with commercial GDH generated higher current. This suggests that using enzymes with lower K m may be advantageous when operating in low glucose environments like tears. The improved TG sensor also demonstrated the potential of integrating Schirmer’s test strip as a tear sampler for self-monitoring of TG.