Photo-antimicrobial efficacy of zinc complexes of porphyrin and phthalocyanine activated by inexpensive consumer LED lamp.

The properties and antimicrobial efficacies of zinc complexes of tetrakis(N-methylpyridinium-4-yl) tetraiodide porphyrin and tetrakis(N-methylpyridinium-4-yl) tetraiodide phthalocyanine impregnated to paper were evaluated. Photo-inactivation of microbes using inexpensive consumer light-emitting diode lamp was assessed on surface of dyed papers. Antimicrobial experiments of phthalocyanine-dyed paper by live cell assessment through colony forming units counting demonstrated 3.72 and 4.01 log reduction against Escherichia coli (E. coli) and Acinetobacter baylyi (A. baylyi) respectively after 1 h of illumination with 35 mW/cm light. The porphyrin-dyed paper exhibited 1.66 and 2.01 log reduction in colony forming units against E. coli and A. baylyi respectively after 1 h exposure with 4 mW/cm light. Both dyed papers were photo-stable after 64 h of continuous exposure with 42 mW/cm light, while phthalocyanine-dyed paper exhibited superior leaching stability in phosphate-buffered saline.