The exceptional and appealing qualities of the polysaccharide biopolymer chitosan, such as biodegradability, biocompatibility and nontoxicity have been successfully utilized in the creation of specialized polysaccharide-based composite material. The bio-nano composites in the current work were prepared by combining curcumin nanoparticles of two distinct sizes that were produced using a green method with carboxymethyl chitosan (CMC). Additional testing methods used for the composite include XRD, TEM, UV-Vis, and FTIR. XRD and TEM provided data on things like grain size, crystalline nature, shape and size respectively. Curcumin interacts with the NH2 group of Carboxymethyl Chitosan (CMC) which is confirmed through FTIR spectra. UV-Vis spectra indicate a blue shift when the particle size decreases. The conductivity of the CMC with curcumin is high than the pristine. The CMC with curcumin enhances the conductivity. The CMC with curcumin nanoparticle S1 has higher conductivity than the curcumin nanoparticle S2 has the lower conductivity. The conductivity for the curcumin with smaller size (9 nm) has higher conductivity(12.35 mS) when compare with larger size (18 nm) of curcumin has the lower conductivity (11.38 mS). The composite with higher conductivity has good antimicrobial activities against C. glabrata and A.niger .The detailed results are presented and discussed.