Effect of surface capping on the biological properties of calcium oxide nanoparticles (CaO-NPs)

Herein, we have investigated and compared biocompatible calcium oxide nanoparticles (CaO-NPs) with different surface chemistries for biological properties. In the study, green synthesis is achieved using an aqueous extract of Potentilla bifurca while chemical synthesized polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB)-coated CaO-NPs are prepared using a facile coprecipitation approach. The nanoparticles are characterized using different techniques including, X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), UV-visible spectroscopy (UV–Vis), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX). Moreover, yield and pH-responsive dispersion studies are also carried out. After comprehensive characterization, the NPs are explored for potential biological properties such as antibacterial, antifungal, antileshmanial, antioxidant, and biocompatibility. Our study reveals that green synthesis results in CaO-NPs with high antioxidant and dispersion properties while chemical synthesis in particular CTAB-coated CaO-NPs exhibits remarkably high antibacterial, antifungal, and leishmancidal properties. For instance, the NPs resulted in 25 ± 1.4 mm and 16 ± 0.4 mm zone of inhibition (ZOI) against Bacillus subtilis and Aspergillus flavus,, respectively, while 81.10% and 79.34% inhibition against the promastigote and amastigote forms of the leishmania tropica. However, none of the NPs displayed hemolytic behavior, affirming the biocompatible nature of all the NPs. Our study thus concludes that surface characteristics play a vital role in defining the biological properties of CaO-NPs and the NPs could be tailored to harness the required biological properties.