Point-of-care devices for thin-film-based biosensors for the detection of glucose, urea, and pH in biological samples

Abstract

The current work focuses on the development and testing of point-of-care (POC) devices—based on a color sensor (CSD) and a fiber-optic spectrometer (FOS)—for healthcare monitoring of biological markers. Agarose-based fluorescent indicator-loaded thin film biosensors (TFBs) were synthesized by co-immobilizing analyte-specific enzymes such as glucose oxidase and urease. This study further evaluates enzyme-immobilized polymer-fluorophore-based thin films for the detection of glucose, urea, and pH in plasma and urine samples. TFB-CSD and TFB-FOS biosensor-coupled devices demonstrated linear detection ranges for glucose (0–40 mM), urea (0–100 mM), and pH (4–9), with rapid response times of 30 s for pH sensing and 2 min for glucose and urea sensing. The sequential results obtained using TFB-CSD were compared with those from TFB-FOS. Both devices were found to accurately detect analytes (expressed as average % recovery): glucose (100.32 % for TFB-FOS and 103.59 % for TFB-CSD), urea (114.30 % for TFB-FOS and 108.49 % for TFB-CSD), and pH (103.49 % for TFB-FOS and 105.21 % for TFB-CSD) in blood and urine samples. © 2025 Elsevier B.V., All rights reserved.