Abstract
At-home testing of glucose levels is crucial for safe monitoring of a
variety of diseases, such as pancreatitis, psoriasis, cirrhosis, acute
myocardial infarction, and, of course, diabetes. Current blood tests are
invasive, leading to the research of alternative biofluids such as
saliva, tears, and sweat. Nevertheless, such fluids are limited in
quantity and contains various interfering molecules, posing stringent
technological requirements. In this study, a simple paper-based glucose
sensor is designed by using the conductive polymer
poly(3,4-ethylene-dioxythiophene) polystyrene sulfonate (PEDOT:PSS) and
a bi-enzymatic solution of Horseradish Peroxidase (HRP) and Glucose
Oxidase (GOx). Unlike most electrochemical glucose sensors, this sensor
employs a chemiresistive mechanism, allowing simple configurations, low
costs, and easy signal measurements. The designed sensor demonstrates a
working range suitable for various biofluid analysis, e.g., saliva, with
a limit of detection of 1.1 µM and a linear detection range of 102 –
104 µM while only requiring 40 µL sample volume. Detection in whole
artificial saliva is also carried out to demonstrate the sensor
applicability. The limited analyte volume required, and the suitable
detection range and limit of detection achieved by this sensor make it
an excellent candidate for developing a non-invasive, at home glucose
meter.