• Use of polyamide-based dental flosses as novel sensing material. • Silver plated polyamide conductive thread electrodes as working and counter electrodes. • EIS in the frequency range from 1 Hz to 100 kHz to detect pH change. • Linear trend between pH change and resistance at 1 kHz. In the present work, we present a novel resistive pH sensor prototype comprising of disposable polyamide-based dental flosses which act as a sensing layer connected to the conductive silver-plated polyamide thread-based electrodes. Without a reference electrode, the prepared dental floss-based sensor was able to detect the pH change of different buffer media by analyzing the variation in the electrical resistance using electrochemical impedance spectroscopy in 1 Hz-100 kHz frequency range. Utilizing dental flosses and thread-based electrode set up, fabricated sensor offers a miniaturized, flexible and promising pH sensing interface suitable for developing implantable and wearable devices for in-vivo applications to ensure oral health.