Antimicrobial resistant biofilms present challenges across healthcare, environmental, and engineered systems, creating a need for alternative materials capable of disrupting biofilm formation and overcoming their resistance. Metal oxide nanoparticles with antimicrobial potential, such as zinc oxide (ZnO) and magnesium oxide (MgO), provide a promising alternative because their nanoscale physicochemical properties which can be controlled through synthesis. Thus, this study investigates the synthesis and optimization of ZnO and MgO nanoparticles and establishes their physicochemical characteristics prior to biological evaluation. ZnO nanoparticles were synthesized through a solvothermal approach, while MgO nanoparticles were prepared hydrothermally using methanol and water as synthesis solvents respectively. Synthesis conditions were varied to investigate their influence on nanoparticle formation and dispersion behavior. The synthesized materials were subsequently characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta-potential analysis, techniques to establish particle morphology, size, and hydrodynamic behavior which gave 20.07nm, 54.17nm and 23,80 Vm for ZnO while 87.07 nm, 101.80 nm and -25.03 Vm for MgO respectively. X-ray diffraction (XRD) confirmed crystalline phase formation and enabled evaluation of crystallite size, Fourier-transform infrared spectroscopy (FTIR) provided information on metal–oxygen bonding and other surface functional groups. The optical spectroscopy revealed characteristic absorption and fluorescence behavior. Comparative analysis revealed synthesis-dependent differences in nanoparticle size, polydispersity, morphology, and physicochemical behavior, demonstrating the importance of controlling synthesis conditions when designing metal oxide nanoparticles for biological applications. The characterization of ZnO and MgO nanoparticle formulations enables a baseline for further biofilm inhibition studies