Novel modified QAC antimicrobial coatings: application, evaluation and functional determination

A series of novel quaternary ammonium compounds (QACs) previously synthesized by the Foucher Research Group containing the core motif R1-(CH2)3-N+ (CH3)2-(CH2)3-R2, where R1 represents functional groups responsible for anchoring the compound to various substrates and R2 represents moieties responsible for altering the activity and surface properties of coated materials are described. R1 groups include benzophenone (-O-C6H4-C(O)-C6H5) 1a-11a for anchoring to polymer surfaces, and organosilane (-Si(OCH3) 3b-10b for anchoring to textiles and fabrics, while R2 groups include linear alkyl chains (-(CH2)n-CH3; n = 11, 17) 1-2 and aryl or alkyl sulfonamide containing moieties (-NH-SO2-CXHY, x = 2-10; y = 5-11) 3-11. These compounds were tested for antimicrobial activity at solid/air interfaces (LDI) and were found highly effective against representative Gram-positive and Gram-negative bacteria (except 7a-8a, 11a). Selective solid/liquid antimicrobial testing (LRI) was performed on 1a, 5a and only 5a was found to be highly effective against Gram-positive bacteria.