ZnO Nanostructures applied in Biosensors

MADRID, R.E.; TRUJILLO, RICARDO M.; SAPPIA, L.D.; TIRADO, MÓNICA; COMEDI, DAVID; ESQUINAZI, PABLO; CATTANI-SCHOLZ, A.

Conferencia; Global Virtual Summit on ?Materials Science and Engineering?; 2020

ConferenceZnO has importanttechnological implications, which attracts special attention from differentfields. It is a promising material and especially in the last few years, in thearea of biosensors. A biosensor is an analytical device, which converts asignal from a molecular recognition element into an electrical signal, or otherkind of signal proportional to the concentration of a defined analyte. With theadvent of nanotechnology, biosensors have been improving in performance and sensitivity.We have studied different properties of nanostructured ZnO to be used toenhance the characteristics of biosensors. On one side, we studied the basis ofthe transport properties of ZnO thin films (TF) and single crystals (SC)towards different solutions. We found that different saline solutions and also,more complex ones, like glucose, by means of the charge of the ions, producesstrong changes in the transport properties of the ZnO TF. The strongest effectwas observed for glucose, which could be explained by the entrapment ofcarriers in the grain boundaries of the TF. On the other hand, we studied ZnOnanoparticles (NPs) immobilized onto gold electrodes, and we found thatphosphonic acid-terminated self-assembled monolayers can enhance theelectrocatalytic behaviour of ZnO NPs immobilized on the gold surface. The resultsindicate the formation of highly stable arrays of ZnO nanoparticles. In bothcases we use impedance spectroscopy to evaluate the electrochemical behaviourof the ZnO?s nanostructures.