Physicochemical Characterization Of Cobalt Carbonate Nanoparticles And Their Dose Dependent Effects On Gut Microbiota In Mice

Abstract

Cobalt carbonate nanoparticles (CoCO₃ NPs) were synthesized using a chemical precipitation approach and systematically evaluated for their physicochemical properties, biocompatibility, and effects on gut microbiota in albino mice. Structural characterization by X-ray diffraction confirmed the crystalline nature of the synthesized nanoparticles, with an average crystallite size of approximately 36 nm. Fourier transform infrared spectroscopy verified the presence of characteristic carbonate and cobalt–oxygen functional groups, while scanning electron microscopy revealed nanoscale morphology with relatively uniform particle distribution. Biocompatibility assessment through hemolysis assay demonstrated a concentration-dependent response, with lower concentrations exhibiting minimal hemolytic activity, whereas higher concentrations induced increased red blood cell membrane disruption. To investigate biological effects following oral exposure, gut microbiota from albino mice were analyzed using conventional microbiological and gram-staining techniques. The control group showed normal density of gram-positive cocci, while low-dose CoCO₃ NP exposure resulted in moderate alterations in bacterial density. In contrast, high-dose exposure caused a noticeable reduction in bacterial population along with clustering behavior, indicating nanoparticle-induced microbial stress. Overall, the findings suggest that cobalt carbonate nanoparticles possess well-defined structural characteristics and acceptable biocompatibility at lower concentrations, while higher doses may adversely affect gut microbial balance. These results highlight the importance of dose optimization and biosafety evaluation for cobalt-based nanoparticles intended for biomedical or environmental applications.