Development and preliminary evaluation of tongue cleaner-based pH and glucose biosensors for salivary assessment.

INTRODUCTION: Saliva reflects both oral and systemic health. Monitoring salivary pH and glucose using tongue cleaner-based biosensors may provide a simple non-invasive method for routine salivary assessment. OBJECTIVE: To develop and preliminarily evaluate separate tongue cleaner-based biosensors for salivary pH and glucose detection in healthy individuals and those with oral disease. MATERIALS AND METHODS: Separate pH and glucose biosensors were fabricated on tongue cleaner platforms. The pH biosensor used an anthocyanin-chitosan-pullulan membrane, while the glucose biosensor incorporated glucose oxidase-functionalized carbon graphite and silver/silver chloride electrodes. Eighty participants aged 18-65 years were included: 40 with dental caries or periodontitis and 40 healthy controls. The glucose sensor was calibrated using glucose standards and validated against the GOD-POD assay. RESULTS: Salivary pH was significantly lower in the study group than controls (6.71 ± 0.41 vs 7.44 ± 0.22; p < 0.001). Glucose resistance values were significantly higher in the study group (39.03 ± 15.54 kΩ vs 10.24 ± 1.13 kΩ; p < 0.001), indicating elevated salivary glucose levels. Very large effect sizes were observed for pH, glucose resistance, and glucose levels. Potentiometric measurements strongly correlated with the GOD-POD assay (r = 0.96; p < 0.001). CONCLUSION: The developed tongue cleaner-based biosensors demonstrated measurable differences in salivary pH and glucose between healthy individuals and those with oral disease. These low-cost, non-invasive biosensors show potential for salivary assessment, although further large-scale validation is required.