Antimicrobial activity of graphite oxide doped with silver against Bacillus subtilis, Candida albicans, Escherichia
G Chavez-Esquivel1, H Cervantes-Cuevas2, L F Ybieta-Olvera2
1Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, Azcapotzalco, Ciudad de México 02200, Mexico; Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico.
Abstract:
In the present study, graphite oxide, graphite oxide doped with 0.8 g AgNO3 named GrO-0.5Ag, and graphite oxide doped with 1.25 g AgNO3 named GrO-1.0Ag (silver-doped graphitic materials) were synthesized by the modified Hummers and chemical doping methods. Subsequently, its antimicrobial activity against Bacillus subtilis, Candida albicans, Escherichia coli, and Staphylococcus aureus microorganisms was evaluated by agar well diffusion test with 1 and 2 mg·ml-1 of material concentrations. The silver-doped graphitic materials were characterized by X-Ray Diffraction, Fourier-Transform Infrared, Raman, X-Ray Photoelectron spectroscopies, and Scanning Electron Microscopy. The GrO-0.5Ag material showed a percentage of inhibition effect of 86, 82, 48, and 45% with respect to the positive control for Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans microorganisms, respectively. Otherwise, the GrO-1.0Ag material showed a percentage of inhibition effect of 54% with respect to the positive control for Bacillus subtilis and less than 50% for the other microorganisms. The material concentrations showed a slight change in the percentage of inhibition effect for all microorganisms. Graphite oxide functional groups, small crystal size, free silver ions, and silver carbonate formation in silver-doped graphitic materials presented a viable alternative to inhibit bacterial growth.
