SnO2 electrolyte-gated thin film transistor for highly sensitive pH detection of beverages.

The pH value is a crucial indicator of the acidity or alkalinity of beverages, directly influencing taste, flavor, shelf life, and consumer health, making pH detection essential in the field of food safety. To enable precise pH monitoring, a SnO₂-based electrolyte-gated thin-film transistor (EGTFT) pH sensor was developed via a low-cost sol-gel process. Experimental results demonstrated that the device operated at a low voltage (0.5 V) and exhibited high sensitivity (78.99 mV·pH -1) beyond the Nernst limit. The superior stability and corrosion resistance of the SnO2 sensitive layer enabled the sensor to maintain current within 97 % of its original value during 14 days of long-term stability test. The actual measurements of pH levels in beverages have demonstrated high accuracy, indicating that the SnO2-EGTFT pH sensor can serve as an excellent platform for highly sensitive and stable pH detection in the food industry.