Microwave-annealed PZTO film: a high-performance pH-sensing membrane fabricated via sol-gel process

Abstract Lead zirconate titanate oxide (PZTO) thin films, fabricated via the sol-gel process, were studied as high-sensitivity pH-sensing membranes for ion-sensitive field-effect transistor (ISFET)-based biosensors. This study evaluated the surface and structural characteristics of PZTO membranes in their as-deposited state and after microwave annealing (MWA) at power levels (600, 1000, 1400, 1800 W). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM) revealed that MWA significantly improved membrane properties by promoting Ti- and Zr-hydroxyl group formation, reducing surface roughness, and optimizing grain size. The 1400 W MWA-treated PZTO membrane exhibited superior pH-sensing performance, achieving 56.9 mV/pH sensitivity, an 11.8 mV hysteresis voltage, and a 9.5 mV/h drift rate, outperforming the as-deposited membrane. These findings highlight MWA as an effective treatment for optimizing PZTO membranes and demonstrate its potential for ISFET-based biosensors in real-time, accurate pH detection. This study advances biosensor technology and provides a foundation for PZTO optimization.