Section II: Chemistry (Calendar‪)‬

8:30 SILVER-IMPREGNATED ALUMINA AS AN ANTIMICROBIAL AGENT**, Gemeia Cameron* (1), David Collart (1), Eric Mintz (2), Olivier Katembo* (2), Conrad Ingram (2) and Godwin Ananaba (1), Department of Biological Sciences, Clark Atlanta University, Atlanta, GA 30134 and (2) Chemistry Department, Clark Atlanta University, Atlanta, GA 30134. The recognition of the anti-microbial activity of oligodynamic metals such as silver has been a basis for the development of many anti-microbial processes and products. More specifically, silver and silver salts have been widely employed, particularly in water disinfection. Nano-sized silver particles have numerous commercial applications, including disinfection of water, food processing and disinfection of healthcare equipment. In Escherichia coli (E. coli), which are vulnerable to silver, it has been suggested that the lipopolysaccharides on their surface contain high affinity binding sites for divalent cations. It has been shown that silver interacts with the cell membranes of bacteria, which alters their mesosomal functions, such as their ability to aid DNA replication. The nature of the bactericidal activity of silver and even more specifically silver-impregnated alumina, its mechanistic details, and properties that influence disinfection are poorly understood. However, we hypothesize that silver in complex with alumina destroys bacteria by oxidation of the plasma membrane and inhibition of its energy metabolism. To study this hypothesis, we exposed E. coli to various concentrations of metallic silver, impregnated on the surface of alumina and determined its effects in compromising cellular integrity and disrupting cellular processes. Our studies reveal that increasing the concentration of silver-impregnated alumina results in a decrease in bacteria viability. This study suggests that silver's ability to kill bacteria is dose dependent. Also, this study suggests silver adsorption upon contact with bacteria. The results of our studies show that silver-impregnated alumina is an effective anti-microbial reagent. Based on this data, we believe that this novel silver anti-microbial reagent is an adequate and cost-effective medium that could be used to improve water quality. (This project was supported by NSF Grant # CTS-0120978, Water CAMPWS, and NIH Grant #GM08247.) 8:45 PHOTOCHEMICAL ANALYSIS OF SUBSTITUTED TETRAPHENYL PORPHYRIN DYES: TETRA AND PENTAFLUOROPHENYL SUBSTITUTION**, Adegboye Adeyemo (1), Nneamaka Enweani* (2), Zachary Gardner* (2), Donovan Tucker* (2) and James LoBue (2), (1) Savannah State University Department of Natural Science and Mathematics. Savannah, GA 31404 and (2) Department of Chemistry, Georgia Southern University, Statesboro, GA 30460. Previous work in this laboratory involved the measurement of the luminescence quantum yield of a trifluorinated tetraphenyl porphyrin against cresyl violet. Photolysis at 488 nm involving the photodestruction of diphenyl anthracene via energy transfer from the trifluorinated tetraphenyl porphyrin was also measured by comparison with methylene blue. Work described here will include similar measurements on 2,3,5,6 tetrafluoro tetraphenyl porphyrin and 2,3,4,5,6 pentafluoro tetraphenyl porphyrin. All dye solutions were dissolved in chloroform. Photolysis was monitored by UV-Vis spectrophotometry using a Shimadzu 2401 PC spectrometer. The photolysis light source was a Coherent Innova 90 Argon Ion laser. Fluorescence was measured using an ISS Phase Modulated Spectrofluorometer.