Bismuth-gold nanohybrid conjugated with a HEX-bound oligonucleotide; a novel nano photosensitizer to combat antimicrobial resistance

Antimicrobial resistance (AMR) leads to a decrease in the adequacy of antimicrobial agents and an increase in the rate of adverse effects and mortality. The main objective of this project is to investigate the synergistic effect of BiAu@NCLin-T ₁ and its substructures as an antimicrobial photodynamic therapy (aPDT) agent to combat microbial resistance. In addition, the effect of photothermal therapy (PTT) on some of the designed nanostructures at a temperature of 40°C was also tested. The antimicrobial test was carried out using the growth curve method against E. coli and S. aureus as Gram-negative and positive model bacteria. Computational methods were used to investigate the stability and entropy of oligonucleotide sequence structures. Various analyses were performed to identify the nanostructures, including Ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and fluorescence analysis. The BiAu@NCLin-T ₁ appeared the significant aPDT impact against the gram-negative E.coli strain at two distinctive oligonucleotide concentrations (1, and 1.5 µM). Based on the results, the outlined nanostructures can act as a photosensitizer (PS), a photothermal treatment agent (PTT), and an antimicrobial agent to combat resistant bacteria.