Smartphone-based colorimetric detection of urinary glucose using a novel green and red/green approach

Abstract

Urine dipsticks are commonly used to detect pathological changes in urine due to their low cost and easy operation, having glucose parameter to detect glucosuria. Despite their advantages, the urine dipstick is ineffective in the early detection of diabetes due to its limitations in the detection of glucose below 100 mg/dl. Here, we present a novel, cost-effective ambient ring light-based smartphone platform to accurately estimate urinary glucose concentrations in lower points utilizing glucose sensors obtained from commercially available urine dipsticks (Mission® and Recombigen™). Glucose sensors changed color from green to brown with the increasing glucose concentration, resulting in a response time of 5 min. In this study, smartphone was used to capture images and analyze Red-Green-Blue (RGB) profiles, extracted with the help of an open-source smartphone-android-based Color Picker app. G intensity was determined to be inversely proportional and R/G intensity to be directly proportional to the increasing glucose concentration. LOD was found to be 6.2 and 24 mg/dl for Mission® glucose sensors with G and R/G respectively. On the other hand, Recombigen™ dipstick glucose sensors, LOD was evaluated as 5.8 and 16 mg/dl with G and R/G respectively. This smartphone-based assessment of glucose using dipsticks can be beneficial in the current screening and diagnostics sector of earlier detection of glucose in urine. © 2025 The Authors