ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Fast and simple glucose assay based on filter paper as enzymes carrier using phone camera detection
Pavla Martinkova, Martin Brtnicky, Jindrich Kynicky, and Miroslav Pohanka
University of Defense, Hradec Králové, Czech Republic
Abstract: Glucose is a typical diagnostic marker of diabetes mellitus but it may be also helpful during diagnosis of some types of poisoning, immunological disorder or long-term stress at hospitalized patients. Diagnosis of diabetes mellitus in time is indispensable for prevention of life-threatening complication and so, accurate and easy device for non-invasive and accurate self-diagnosis is necessary. Simple assay based on filter paper with chitosan layer and with immobilized enzymes glucose oxidase and peroxidase and phone camera detection has been proposed for home-care glucose detection in urine. Data were processed in RGB (red–green–blue) color model when blue color channel showed the best sensitivity to changing glucose concentrations. Assay exerted linear regression from 0 to 4 mmol/l and limit of detection was set to be 166 µmol/l. Assay was not influenced by any interfering substances including maltose, sucrose, sorbitol or fructose or by urine matrix substance such as bovine serum albumin, ascorbic acid, uric acid or urea. Measurement of glucose from spiked urine samples reveals also no influence of the matrix on the assay. Long-term stability was measured and filter papers coated by enzymes showed excellent stability for at least 9 weeks without any special treatment or package. In comparison with differently modified filter paper, filter paper with both chitosan and enzymes showed the best sensitivity to changing glucose concentration. In a conclusion, simple (phone camera detection) and fast (3-min reaction) assay for quantitative detection of glucose from urine was optimized.
Keywords: Glucose assay ; Phone camera detection ; Home-care analysis ; Glucose oxidase ; Horseradish peroxidase ; Chitosan
Full paper is available at www.springerlink.com.
Chemical Papers 72 (11) 2719–2728 (2018)