Structural, optical, antimicrobial properties with drug loading and drug release of five different ZnO nano and sub-micron particles for biomedical applications

In the present study, a hydrothermal method has been used to optimise five morphologies of ZnO by varying the process parameters for biomedical applications. X-ray diffraction (XRD) patterns have revealed the single phases of ZnO peaks with hexagonal wurtzite structure. The crystallite sizes of different ZnO samples were depicted as 37.99 nm, 52.51 nm, 61.26 nm, 62.14 nm, and 66.02 nm, respectively. The field emission scanning electron microscopy (FE-SEM) shows that ZnO powders have different morphologies like hexagonal rod-like, flakes-like, spindle-like, flower-like, and dumbbell-shaped. The ZnO particles are randomly orientated, and the average particle sizes are 230 nm, 80 nm, 203 nm, 207 nm, and 320 nm, respectively. The elemental dispersive spectroscopy (EDS) reveals that only Zinc (Zn) and Oxygen (O) peaks are available, and no other impurities have been found. The photoluminescence (PL) shows that samples have different absorptions intensities. The 5-Flourouracil (anticancer drug) was successfully loaded and its slow-release profile has been investigated. The drug loading and drug release profile show the potential for drug delivery. The antimicrobial activity shows a significant zone of inhibition (ZOI) against both gram-negative (E. coli) and gram-positive (S. aureus) bacteria. The maximum ZOI is shown for spindle shaped ZnO against both bacteria.