Joselyn Nathania Cathrine Sembiring, I. Dewa Putu Hermida, Indra Pardede, Diki Purnawati, Shobih Shobih
Sustainable fabrication routes are essential for developing the next generation of chemical sensors, particularly for environmental monitoring applications. This study presents the pH-sensing performance of ZnO-Chitosan (ZnO:CS) composites fabricated via a water-based screen-printing method as a green technology approach. Zinc Oxide (ZnO), a non-toxic and chemically stable semiconductor, was combined with chitosan (CS), a biodegradable natural polymer, to enhance film uniformity, adhesion, and ionic conductivity. Structural and morphological characterizations were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results confirmed the hexagonal wurtzite structure of ZnO and the formation of an amorphous ZnO:CS composite, while SEM revealed a uniform film morphology with a thickness of approximately 60 μ m and strong adhesion to the substrate. Three ZnO:CS ratios (1: 2,1: 4, and 1: 8) were tested in buffer solutions of pH 4, 7, and 10. All sensors exhibited excellent linearity, with sensitivities ranging from -1.1 mV/pH to -1.95 mV/pH. The ZnO:CS 1:2 composition demonstrated the fastest response time (22.2 s) and consistent potential stability. These results highlight the potential of the ZnO:CS composite as a low-cost, eco-friendly, and reliable material system for potentiometric pH sensors, supporting the advancement of green technology for sustainable, real-time water quality monitoring. © 2025 IEEE.
Sumatera Institute of Technology, Department of Physics, Lampung, Indonesia; Research Center for Electronics, National Research and Innovation Agency of Indonesia, Bandung, Indonesia