Nanostructured ZnO films: A study of molecular influence on transport properties by impedance spectroscopy

SAPPIA, LUCIANO; TRUJILLO, MATÍAS; LORITE, ISRAEL; MADRID, ROSSANA; TIRADO, MONICA; COMEDI, DAVID; ESQUINAZI, PABLO

Nara City

Simposio; 23th International Symposium on Metastable, Amorphous and Nanostructured Materials: ISMANAM 2017; 2016

WPI Advanced Institute for Materials Research, Tohoku University, SENDAI, JAPAN

ZnO is a material that has important technological implications and has attracted special attention of researchers from different fields. It is a promising material for different applications, such as electronics, optoelectronics or piezoelectricity. But ZnO also attracted new attention forbiosensor applications.Nanomaterials based on ZnO have been used to build glucose sensors due to its high isoelectric point, which is important when a protein like Glucose Oxidase (GOx) is attached to a surface. It also creates a biologically friendly environment to preserve the activity of the enzyme.In this work we study the electrical transport properties of ZnO thin films and single crystals in contact with different solutions by using impedance spectroscopy. We have found that the composition of the liquid, by means of the charge of the ions, produces strong changes in the transport properties of the thin film. The enzyme GOx and phosphate buffer solutions have the major effect in the conduction through the films, which can be explained by the entrapment ofcarriers at the grain boundaries of the thin films. These results can help to design a new concept in glucose biosensing [1].[1] L.D. Sappia, M.R. Trujillo, I. Lorite, R.E. Madrid, M. Tirado, D. Comedi and P. Esquinazi, Materials Science and Engineering B 200 (2015) 124-131.