resumo
Fish bones were converted into materials consisting of silver phosphate (Ag3PO4), beta-calcium phosphate (beta-Ca-3(PO4)(2), beta-TCP) and hydroxyapatite (Ca-10(PO4)(6)(OH)(2), HAp), as well as of metallic silver (Ag-0), with a simple treatment in solution and calcination (650 or 1000 degrees C). The antibacterial activity of the material was measured in the dark and under UV and white light irradiation; this is the first time that an Ag3PO4-based material was tested under these conditions. Results showed light-enhanced antibacterial properties toward Gram-positive and Gram-negative strains (Methicillin-resistant Staphylococcus aureus -MRSA, Escherichia coli,Pseudomonas aeruginosa), with inactivation rates of up to 99.999% under UV light, and 99% for E. coli under white light (artificial indoor lighting). The photocatalytic activity was also tested, and the degradation of methylene blue dye was observed under both UV and white light. Even if the MB degradation was to a smaller extent under white light, it was approximately twice that of the commercial photocatalyst P25. This work demonstrates the valorisation of a food industry by-product such as fish bones to form a potentially valuable material, with important applications in self sterilizing surfaces and environmental remediation. (C) 2014 Published by Elsevier B.V.
palavras-chave
STAPHYLOCOCCUS-AUREUS MRSA; PHOSPHATE-BASED MATERIALS; TRICALCIUM PHOSPHATE; TITANIUM-DIOXIDE; TREATMENT PLANTS; METHYLENE-BLUE; AG3PO4; WATER; SEMICONDUCTOR; DEGRADATION
categoria
Chemistry
autores
Piccirillo, C; Pinto, RA; Tobaldi, DM; Pullar, RC; Labrincha, JA; Pintado, MME; Castro, PML
nossos autores
David Maria Tobaldi
Investigador
João António Labrincha Baptista
Professor Catedrático
Rob Pullar
ColaboradorProjectos
agradecimentos
Authors acknowledge PEst-C/CTM/LA0011/2013 and PEst-OE/EQB/LA0016/2013 programs. The work was also funded through the iCOD project (Inovadora Tecnologias para a Valorizacao de Subprodutos do Processamento do Bacalhau, contract QREN AdI I vertical bar 466). R.C. Pullar wishes to acknowledge the FCT Bolsa de Investigacao SFRH/BPD/97115/2013 for supporting this work. C. Piccirillo thanks FCT for her research grant (SFRH/BPD/86483/2012). D.M. Tobaldi is grateful to the ECO-SEE project (funding from the European Union's Seventh Framework Program for research, technological development and demonstration under grant agreement no. 609234. (The views expressed are purely those of the authors and may not in any circumstances be regarded as stating an official position of the European Commission).