Hybrid graphene oxide-immobilized silver nanocomposite with optimal fabrication route and multifunctional application

Herein, the surface modification of graphene oxide with silver nanoparticles was examined with the type of reducing agents, the reducing agent:AgNO3 mass ratio, reduction temperature, reduction time, and AgNO3:GO mass ratio. The optimal fabrication condition was determined based on the AgNPs density on GO, AgNPs size, and the antibacterial activity of the Ag/GO by plate colony-counting and optical density methods. The as-prepared materials were analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. Results revealed that the appropriate reducing agent is ascorbic acid (AA) with the conditions: the ratio AA:AgNO3 = 1:1; reaction at 40 degrees C in 10 min with AgNO3:GO ratio of 1.25:1. More than 99.99 % of bacteria was inhibited, with a minimum bactericidal concentration of 50 and 100 mu g/mL for P. aeruginosa, and S. aureus, respectively. Furthermore, the materials were surveyed in terms of their interface sorption and sensing applications. The maximum adsorption capacity of the nanocomposite reached 98.04 mg/L at 40-100 mg/L methylene blue, while the limit of detection for detecting Hg(II) in water was indicated to be 223 nM. Therefore, Ag/GO has shown sustainably promising usage for multiple purposes.

Automated summary

This study investigated the optimal conditions for the surface modification of graphene oxide with silver nanoparticles, revealing high antibacterial activity against P. aeruginosa and S. aureus, as well as promising applications in interface sorption and sensing. The nanocomposite showed a maximum adsorption capacity for methylene blue and a low detection limit for Hg(II) in water, indicating its sustainable potential for multiple purposes.