Copper Nanoparticles by Rhodotorula diobovata as an antimicrobial agent against Antibiotic Resistance

Copper's distinctive physical and chemical characteristics render it a prevalent metallic element. This research aimed to explore the eco-friendly, straightforward, and cost-effective green synthesis of copper nanoparticles (Cu-NPs) using Rhodotorula diobovata Strain B2© and copper sulphate as starting material. The influence of the incubation time and the effect of biosynthesis Cu-NPs on the growth of bacteria and yeast were studied in this research. The direct and rapid formation of Cu-NPs occurs when Rhodotorula diobovata interacts with Cu+2 ions, which is visually indicated by a color transition from light blue to dark bluish-green. UV-Vis, FT-IR, DLS and zeta-potential, TEM, and EDX were used to characterize the shape, size, and structure of the produced Cu-NPs. The UV-Vis measurement revealed a surface plasmon resonance (SPR) peak at 606.5 and 622.5 nm due to the capping activity of Rhodotorula diobovata biomolecules in the synthesis of Cu-NPs. Energy dispersive spectroscopy (EDX) revealed low-intensity peaks of phosphorus (P), calcium (Ca), and potassium (K) elements and high-intensity metallic peaks of copper (Cu), oxygen (O), and sulfur (S). The synthesis of Cu-NPs is triggered by the presence of functional groups -OH, C=C, and C-H, as proven by FT-IR analysis. The TEM investigations also showed that the particles ranged in size from 33 to 63 nm and had a spherical form. DLS and zeta-potential analysis indicate that the particle sizes are 22.1 nm and 19.5 nm, and the zeta-potentials are -26.8 and -17.3, confirming the stability of the Cu-NPs. The antibacterial activity of Cu-NPs against Staphylococcus aureus from diabetic foot infection and E. coli and Candida albicans from vaginal swabs was demonstrated. The produced Cu-NPs' hemolytic activity was comparable to that of the control Ringer solution.