Electrocatalytic Zeolite 3A-based sensor for ultra-sensitive glucose monitoring

Non-enzymatic glucose sensors allow ultralow trace detection in saliva and other biofluids of significant interest. We report a novel zeolite 3A–based non-enzymatic glucose sensor for indirect detection via zeolite electrocatalysis, leveraging its porous structure and ion-exchange properties for sensitive, stable sensing. A flexible sensor was fabricated by facile deposition of a zeolite/vegetable oil mixture onto a silver-coated Kapton substrate. The proposed transduction mechanism is based on the glucose-to-fructose isomerization, with charge variation mediated by the rapid deprotonation of hexoses, a process significantly faster than isomerization and closed-hexose anion formation. the sensor exhibited significantly higher sensitivity at lower glucose concentrations of 6.68 μA mM−1·cm−2. At lower concentrations, the linear regression coefficient was R2 = 0.93, whereas at glucose concentrations above 2 mM, the sensitivity was set to 1.00 μA mM−1·cm−2.correlation coefficient decreased to R2 = 0.87. The limit of detection (LOD) was determined to be 0.1 μM. Overall, the wide linear range, cycle-to-cycle stability, and strong low-concentration sensitivity achieved here lay the groundwork for future validation in non-invasive biological matrices.