Wearable transdermal microneedle patch based on photonic crystal hydrogel for glucose monitoring

Daily blood glucose monitoring is the cornerstone of diabetes management. Research efforts have been made on developing non-invasive or minimally invasive point-of-care testing system that can minimize the inconvenience of such daily test bringing to diabetes. Hereby, we develop a wearable and portable microneedle based biosensor for in situ glucose detection in an enzyme free and minimally invasive way. The photonic hydrogel film integrated inside the microneedle platform is functionalized with phenylboronic acid and displays glucose responsiveness. Presence of glucose in the chemical matrix of interstitial fluids can be distinguished with naked-eyes via the color changes of the hydrogel film. Quantification of glucose is achieved by analyzing color of hydrogel film with the facilitation of a mobile phone; thereby fast and direct diagnosis is enabled. Extraction of interstitial fluids and sensing of glucose within the psychological range was successfully demonstrated on porcine skin as human skin model. The developed microneedle platform provides a promising tool for detecting other health related analytes in an enzyme-free way with minimal invasiveness.