A novel atmospheric pressure plasma jet (APPJ) device using argon and oxygen gases was utilized to synthesize and deposit silver particles into pure cotton fabrics. The main goal of the study was to test the efficiency of the novel APPJ system for materials processing for antibacterial application. With maintained electrode distance to obey Paschen's Law, silver electrodes were placed in a glass tube powered by 15 kV. Flow rates of argon and oxygen were kept constant at 15 LPM and 5 LPM, respectively. Plasma species and electron temperature were identified using the optical emission spectroscopy results. Pure cotton fabrics were exposed to plasma for 1 min, 3 mins and 5 mins. Scanning electron microscopy and x-ray fluorescence revealed that silver particles were successfully sputtered on fabric samples. Moreover, plasma treatment also enriched the cotton samples with antibacterial property against Escherichia coli and Staphylococcus aureus as determined by modified standard disk diffusion method. These results demonstrated the surface-immobilization of plasma-synthesized silver nanoparticles on cotton fibers and the promising performance in antibacterial applications.