Fabrication and surface characterisation of c-ZnO loaded TTDMM dendrimer nanocomposites for biological applications

Abstract

The paper reports synthesis, characterisation and biological assessment of c-ZnO NP loaded TTDMM nanocomposites (cZTNCs) using c-ZnO NP and trimesoyl 1,3,5-trimethyl malonate ester (TTDMM) in 3:1 ratio in ethanol at 35 °C for 24 h. UV absorption and FTIR stretching frequency (SF) both infer a development of cZTNCs. TTDMM hydrophobicity facilitated the c-ZnO NP 1:1 dispersion and its size reduction, well supported by DLS and TEM studies having ζ-potential (27.04 mV) and size (17.76 nm) respectively. The NCs size was slightly lower than c-ZnO NP (20 nm) without structural conformation depicted via bond length (0.19660 nm) retrieved from XRD. The structural and morphology behaviour of c-ZnO NP accumulated inside the void spaces of TTDMM depends on their lone pair electron (LPE), pi-electron (PE), delocalisation energy (DLE) and hydrophobicity were investigated using SEM, AFM and TGA. The NCs have revealed highest DPPH· scavenging (84.74%) at 160 μg/mL than c-ZnO NPs. Antimicrobial activity was assessed that displays both cZTNCs and c-ZnO NPs have significant bactericidal efficacy against gram positive (Bacillus subtilis; Staphylococcus aureus and gram negative bacteria (Klebsiella pneumoniae; Proteus vulgaris) but no effect against fungus (Candida albicans). Although, anticancer potency against HeLa cells line was performed where cZTNCs proved to be more active than c-ZnO NPs. Moreover, anticancer activity depicted a direct dose dependent correlation with antioxidant assessment.