Application of Room Temperature Photoluminescence From ZnO Nanorods for Salmonella Detection

ZnO nanorods grown by gaseous-disperse synthesis are confirmed by XRD analysis to have the wurtzite crystal structure. The obtained crystallites, as found from SEM studies, are 57 ± 9 nm in diameter and 470 ± 30 nm long on the average. Two emission bands of photoluminescence from ZnO nanorods observed at room temperature are centered at 376 and 520 nm. A biosensitive layer is prepared by immobilization of anti-Salmonella antibodies from liquid solutions on the ZnO surface. Immobilization of the biosensitive layer onto ZnO nanorods is found to increase the intensity of PL. After further reaction with Salmonella antigens (Ags), the PL intensity is found to decrease proportional to Ag concentrations in the range of 10² - 10⁵ cell/ml. The possible mechanism of biosensor response is suggested and discussed.