Hybrid nanomaterials for biomedical sensors

Abstract

The energy industry is transitioning towards green and ecological power sources, and as a result there is a growing need for hydrogen detectors, which serves as clean and versatile energy carriers. On the other hand, biomedical diagnostics is currently researching various biomarkers exhaled in breath, such as ammonia, 2-propanol, acetone and hydrogen. In this work, Al2O3/CuO gas sensing structure coated with ZIF-8 has been studied for selective enhancement of sensing response for acetone vapor at an operating temperature of 275 and 300 °C. Composite metal-oxide has a granular structure which improves contact with detected gases. XRD study shows the presence of three different phases (CuO, Cu2O, and CuAl2O4) of copper oxide structures following the deposition of the Al2O3on it. EDX shows a homogenous distribution of elements and confirms the elemental composition of Al2O3/CuO films. The ZIF-8 coated Al2O3/CuO nanostructures shows highest gas sensing response (105%) to acetone at an operating temperature of 300 °C with a response and recovery times of 7 s and 43 s, respectively. On the other hand, the gas sensing response (85%) for hydrogen gas was observed at 300 °C with a response and recovery times of 3 s and 9 s, respectively. This work results indicate a way to enhance gas sensing performance by using hybrid nanomaterials, including Al2O3/CuO films with ZIF-8 coating. The electrostatic interaction occurs between the oxygen in the carbonyl group with the metal center (Zn2+) of ZIF-8. The hybrid structures developed here are very important for hydrogen gas detectors, given their dual role in implementing clean energy solutions and improving breath-based biomedical diagnostics.