Towards Point-of-Care Insulin Detection.

Good glucose management through an insulin dose regime based on the metabolism of glucose, helps millions of people worldwide manage their diabetes. Since Banting and Best extracted insulin, glucose management has improved due to: the introduction of insulin analogues that act from 30 minutes to 28 days, improved insulin dose regimes, and portable glucose meters, with a current focus on alternative sampling sites that are less invasive. However, a piece of the puzzle is still missing -the ability to measure insulin directly in a Point-of-Care device. The ability to measure both glucose and insulin concurrently will enable better glucose control by: providing an improved estimate for insulin sensitivity, minimising variability in control, and maximising safety from hypoglycaemia. However, direct detection of free insulin has provided a challenge due to the: size of the molecule, the low concentration of insulin in blood, and selectivity against interferants in blood. This review summarises current insulin detection methods from immunoassays to analytical chemistry, and sensors. We also discuss the challenges and potential of each of the methods towards Point-of-Care insulin detection.