Using piezoelectric nanoarrays for ultrasensitive chemical detection

Nanostructured semiconductors, which have been touted for their applications in energy harvesting and solar cells, are now being explored for their use as chemical detectors. This is due to their tunable morphology, structure diversity, large surface-to-volume ratio, and high active surface area.

Mei et al. created a flexible piezo-electrocatalytic sensor made from zinc oxide nanoarrays to detect hydrogen peroxide, an important indicator in biological and medical fields. For example, high concentrations in body fluids can indicate health problems such as diabetes, skin diseases, cancer, and neurodegeneration.

The researchers created their detector by growing nanoarrays on gold interdigital electrodes using a low-cost hydrothermal process. This method effectively coupled electrical excitation and external strain-induced piezoelectric polarization to promote catalytic reactions.

When the sensor was tested, it showed unexpectedly high detection sensitivity of the hydrogen peroxide, outperforming most other methods. A finite element analysis showed this improved sensitivity was enabled by the synergy of the polarization charge and electrical excitation of the piezoelectric effect, which increase the redox process on the zinc oxide surface.

“Our work shows that it is feasible to use piezoelectric materials to improve the sensitivity and the detection limit of chemical sensors,” said author Jun Zhang.

The team is continuing to work on the sensors to improve their stability for complex environments, such as those with extreme temperatures and pH. They additionally plan to study the piezoelectric effect of two-dimensional materials to explore their use in gas, photoelectric, pH, and other sensors.

Source: “Piezoelectric ZnO nanoarrays for catalytic detection of H₂O₂ with ultra sensitivity,” by Houshan Mei, Xianghong Liu, Yixin Song, Bing Teng, Degao Zhong, and Jun Zhang, Applied Physics Letters (2023). The article can be accessed at https://doi.org/10.1063/5.0146730 .

This paper is part of the Energy Conversion and Storage in Functional Dielectrics Collection, learn more here .