Enhanced antifungal activity of fluconazole conjugated with Cu-Ag-ZnO nanocomposite

Cu-Ag-ZnO nanocomposite (NC) has been successfully synthesized by mechanical alloying the Cu, Zn and Ag powder mixture under Ar atmosphere within 4 h of milling. The nanocomposite is then conjugated with the antifungal drug fluconazole by adding 5 wt% powdered drug to the NC and mechanical alloying the total powder mixture for one more hour. The Rietveld refinement of XRD data and FTIR spectrum analyses reveal the detailed structural and microstructural characterizations of the nanocomposite-drug conjugate (NC-DC). Presence of Cu, Ag, ZnO and drug in the 5 h milled powder are confirmed by analyzing TEM images and FESEM-EDS spectrum. Results obtained from FESEM and TEM images reveal the measure of particle size of the nanocomposite-drug conjugate and it agrees well with the crystallite size obtained from the Rietveld refinement. A significant antifungal activity of NC-DC against Candida sp. fungi has been revealed using disk agar diffusion method. Minimum inhibitory concentration (MIC) test confirms that NC-DC with only 5 wt% fluconazole produces similar antifungal activity of the pure (100 wt%) and conventional fluconazole. Thus, the conjugation of conventional drug to a nanocomposite results in enhancement of drug efficiency by a factor 20 folds. This is very important, particularly, for those antibiotics which are very effective in controlling several epidemic diseases but show intense side effects when used at higher dose and/or for a longer duration.