Development of ZNR-calcium biosensor application

H A Wahab, A A Salama, A A El Saeid and I K Battisha

Abstract

For sensitive Ca²⁺ biosensor fabrication, zinc oxide nanorods (ZN_R) were coated with calcium ionophore membranes to detect Ca²⁺ ions concentration. For preparing ZN_R samples two different layers were deposited by consecutively using two different methods: the former method was the sol-gel method and the later one was the aqueous chemical growth (ACG) method. Biosensors with four different substrate kinds, conducting plastic substrate (P), silicon substrate (S), silver wire substrate (W) and borosilicate glass capillary tube tip substrate (T) were used as working electrodes for calcium concentration determination Ca²⁺ biosensor were initially checked potentiometrically in two solutions: the CaCl₂ solution ranging between 100 mM and 100 nM and cells serum in human blood. Four prepared working electrodes morphologies and structures were characterized by field emission high resolution scanning electron microscopy