Cysteine-Coated Cadmium Sulfide Nanoparticles Conjugated with Curcumin for Antimicrobial Activity

Nanoparticles have several applications in drug delivery. Attaching therapeutics to specially designed carriers enables precise delivery to specific cells. Nanostructures have unique physicochemical and biological features, such as an increased reactive surface area and the ability to pass through tissues and cell walls due to their small size, making them a promising material for biomedical applications. Cysteine-coated cadmium sulfide nanoparticles were prepared using a wet process at high pressure and temperature, followed by curcumin conjugation. The antioxidant, anticarcinogenic, and anti-inflammatory properties of curcumin are well acknowledged. Cadmium sulfide nanoparticles are of extremely good semiconducting material that shows fluorescence at a particular wavelength in spectrophotometric analysis. X-ray diffraction (XRD) of the nanocomposite was conducted to verify the crystalline nature of nanoparticles and to find the average crystallite size of cadmium sulfide nanoparticles. The Fourier-transform infrared spectroscopy (FTIR) confirmed the conjugation of cysteine with CdS and curcumin. Antibacterial activity of the synthesized material against Escherichia coli (E. coli) cells was assessed at different concentrations. The antibacterial activity of conjugated cadmium sulfide nanoparticles against E. coli bacteria was examined using the well diffusion method. The results showed that cadmium sulfide nanoparticles coated with cysteine and conjugated with curcumin had better cytotoxicity against bacterial infections caused by E. coli bacteria.