Sensitive Light-Induced Thermoelastic Spectroscopy-Based Oxygen Sensor With a Perovskite-Modified Quartz Tuning Fork

The concentration of oxygen (O-2) plays a crucial role in the metabolic respiration, maturation, and ripening processes of fruits. In this study, we propose a novel method for gas detection called light-induced thermoelastic spectroscopy (LITES), which utilizes a quartz tuning fork (QTF) coated with a thin film of CH3NH3PbI3 perovskite. By creating a Schottky junction with silver electrodes on the surface of QTF, the photoelectric and thermoelastic effects were coupled by the CH3NH3PbI3-QTF, thereby enhancing the sensor's detection sensitivity. In addition, encapsulation was taken to ensure the long-term stability of the CH3NH3PbI3-QTF sensor. We applied the LITES technology to investigate O-2 concentration during the storage and decay process of strawberries. By monitoring the fluctuations in O-2 concentration, we were able to estimate the degree of strawberry decay. Our findings demonstrate that this low-cost, innovative technique holds promise for replacing conventional photodetectors and has a great potential to apply in studying gas exchange in food packaging and storaging.