A new way was used to modify the thermal, electrical, optical, and antimicrobial properties of polyaniline by embedding a nanosized metal in the polymeric matrix. The sequence of fabrication was as follows: first, preparing a silver colloid by gamma-irradiating the precursor and then, aniline was polymerized in the colloid using different molarities of dopant and silver. The obtained Ag colloid and the polymer / Ag nanocomposites (NCs) were studied for their properties using TGA, electrical measurements, UV-Vis spectroscopy, FTIR, TEM, SEM, DLS, SAED, and EDX. The particle size of the Ag colloid is ranged from 7 to 17 nm. The conductivity of NCs increased with increasing dopant, while an unexpected reduction of conductivity was obtained with the increase of Ag content due to some agglomerations. All the prepared NCs exhibited medium to high antibacterial activity against Escherichia coli and Staphylococcus aureus reaching the maximum efficiency at PANI: Ag: dopant molar ratio of 1:1:0.83. Also, an electrostatic interaction has been generated between the polyaniline chains and the free electrons around Ag NPs leading to a conjugating electron cloud in the produced NCs. This electronic behavior facilitates the use of the prepared NCs as supercapacitors, sensors, photocatalysts, or antibacterial materials.