Silver nanoparticles and carbon black were incorporated into poly (styrene-co-acrylic acid) using an eco-friendly, emulsion aggregation (EA) approach, with final application as an antibacterial electrophotographic printing ink, called toner. This approach was based on dispersing and coagulating the nanosilver (nAg) and carbon black (CB) particles in the styrene–co-acrylic latex (previously synthesized by the emulsion polymerization). Transmission electron microscopy (TEM), X-ray powder diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray (SEM–EDX), and thermogravimetric analysis (TGA) revealed the silver nanoparticles were located in the polymeric structure of the toner. The TEM images showed that the nAg had an average particle size of ~ 50 nm. The antibacterial properties were determined using the agar-well diffusion method against gram-negative Escherichia coli. The nanocomposite produced via the emulsion aggregation method showed highly potent antibacterial activity toward bacteria compared with the neat black toner, which makes it useful in antibacterial printing applications. The antibacterial property was observed to increase with the concentration of the silver powder, with a nonlinear behavior.