Comparative Analysis of Eugenol-Loaded Ag-Co and Unloaded Ag-Co Bimetallic Nanoparticles Against Escherichia coli

Recent developments in nanotechnology have revealed the significance of bimetallic nanoparticles for various applications. This study reveals the facile green synthesis of Ag-Co bimetallic nanoparticles using eugenol. A comparative analysis of Eugenol-loaded Ag-Co and unloaded Ag-Co bimetallic nanoparticle (BNPs) was done to investigate their antibacterial and antioxidant activity using flow cytometry. The biosynthesized Eugenol-loaded and unloaded BNPs were evaluated for antibacterial activity against Escherichia coli . The antioxidant activity was analyzed by using a DPPH scavenging activity assay and flow cytometry. UV–Vis spectroscopic analysis of synthesized eugenol-loaded and unloaded BNPs showed absorbance at 257 nm and 240 nm, respectively. FTIR analysis showed the peak range in the 500–4000 cm- 1 corresponds to different functional groups. Zeta potential confirms the formation of stable and uniformly synthesized BNPs. EDX and SEM analysis confirm the elemental compositions and the size of the BNPs, respectively. Flow cytometric analysis revealed the live-dead parameters of Escherichia coli , when exposed to different concentrations of Eugenol-loaded Ag-Co (Eu@Ag-Co) and Unloaded Ag-Co BNPs. In addition, comparative MIC and MBC values of eugenol-loaded and unloaded BNPs were obtained for Escherichia coli. The Antioxidant activity revealed the comparative higher significant DPPH scavenging activity of Eu@Ag-Co. Moreover, the flow cytometric analysis confirmed the higher antibacterial efficacy of Eu@Ag-Co over unloaded Ag-Co BNPs by showing a higher percentage of dead cells. The study determined the enhanced antibacterial and antioxidant activity of nanoparticles by Eugenol loading and advocated it to be a better therapeutic approach. This study encourages the use of biosynthesized loaded-phytochemicals BNPs over unloaded BNPs. Graphical Abstract