Poly(4-vinyl pyridine) (p(4-VP)) particles were synthesized by a simple micro-emulsion polymerization technique using sodium dodecyl sulfate (SDS) as surfactant. The prepared p(4-VP) particles were then treated various modifying agents with different functional groups. The modifying agents used in the modification of p(4-VP) particles are N-alkyl quaternizing agents such as 2-bromo ethanol (-OH), 4-bromo butyronitrile (-CN), and 2-bromoethylamine hydrobromide (-NH2). The functional groups on the modified p(4-VP) particles were confirmed by FT-IR spectrometry and zeta potential measurements. The size of p(4-VP) and modified p(4-VP) particles is between 300 and 700 nm, and the zeta potentials of modified p(4-VP) particles were varied between 2 and 45 mV. Moreover, a second post-modification was carried out on 4-bromo butyronitrile modified p(4-VP) particles by amidoximation. The modified p(4-VP) particles were also tested for their antimicrobial effects against various bacteria such as Staphylococcus aureus, Bacillus subtilis, and Escherichia coil. It was found that p(4-VP) do not posses antimicrobial properties, whereas the modified forms especially p(4-VP)(+) and p(4-VP)(+)-NH3+ showed highly bactericidal characteristics. Due to the positive charge by means of new functional groups generated on p(4-VP)-based particles by modification, the absorption of oppositely charged reagents such as fluorescein sodium salt (FSS) was increased drastically. For example, the absorption capacity of unmodified p(4-VP) was increased to 93.3, 93.5, and 93.6 form 37.6 mg for p(4-VP)(+), p(4-VP)(+)-NH2, p(4-VP)(+)-NH3+, respectively. Moreover, upon modification, except Cu(II), Co(II) and Ni(II) absorption capacities were increased from about 15.9, and 22.1 mg to 21.1 and 39,1 mg per gram particles. (C) 2013 Elsevier Inc. All rights reserved.