Citrus sinensis Seed-Mediated Gold Nanoparticles for Combating Diabetes and Bacterial Infections: A Promising Multifunctional Nano Formulation

This investigation explores the successful synthesis and comprehensive characterization of Citrus sinensis seed-mediated gold nanoparticles designated as C-AuNPs. Visual confirmation of synthesis was achieved through a distinct ruby red color change in the reaction mixture, followed by UV-Visible spectroscopy, which revealed a characteristic peak absorbance at 522 nm due to the Surface Plasmon Resonance (SPR) phenomenon associated with gold nanoparticles. Transmission Electron Microscopy (TEM) analysis demonstrated uniform, spherical nanoparticles with an average size of 19 nm, ideal for biomedical applications. Dynamic Light Scattering (DLS) revealed a hydrodynamic size of 55 nm in the hydrated state, while a negative zeta potential of −17 mV indicated colloidal stability. C-AuNPs exhibited significant antibacterial activity against both Gram-negative and Gram-positive bacterial strains, surpassing the performance of levofloxacin. Lower Minimum Inhibitory Concentration (MIC) values against bacterial strains further supported their enhanced efficacy, potentially due to interactions with bacterial cell membranes. Furthermore, C-AuNPs demonstrated potent inhibition of α-amylase and α-glucosidase enzymes involved in glucose metabolism, with IC50 values comparable to the anti-diabetic drug acarbose. This suggests their potential as anti-diabetic agents, with the ability to regulate blood sugar levels. C-AuNPs exhibit unique optical, structural, and electrostatic properties, making them promising candidates for diverse biomedical applications. Their small size, stability, antibacterial efficacy, and anti-diabetic properties position C-AuNPs as valuable assets in the realm of nanomedicine and therapeutics, warranting further exploration and development.