Ag-dopirani fluorapatitni nanomaterijali dobijeni postupkom neutralizacije

Abstract

Srebrom dopirani fluorapatiti (AgFAP) su sintetisani postupkom neutralizacije (reakcija Ag2O rastvarenog u HF i H3PO4 sa suspenzijom Ca(OH)2). [1] Sintetisani uzorci AgFAP imali su procentnu zastupljenost jona srebra ([Ag/(Ag + Ca)]·100%) od 0.001, 0.01 i 1%. Rendgenska difraktometrijska (XRD) analiza uzoraka FAP i AgFAP pokazala je da su položaji difrakcionih pikova slični i da su u skladu sa ASTM podacima za fluorapatite (Slika 1). FAP kao materijal ima kristalnu rešetku sa heksagonalnom P63/m prostornom grupom, sa dva strukturno različita položaja Ca2+ jona (Ca1 (4f) i Ca2 (6h) položaji). FTIR and SEM analize pokazale su da su čestice AgFAP uzoraka homogene i nano-veličine. Fluorescencija AgFAP uzoraka je pomerena ka zelenom regionu, u odnosu na fluorescenciju FAP nanočestica (u ljubičastom regionu vidljivog dela spektra). MCR ALS analize su pokazale formiranje dva maksimuma u AgFAP fluorescentnom spektru (na 420 i 520 nm), kao posledica dopiranja Ag+ jona u Ca1 (4f) položaj FAP rešetke (Slika 1). Rezultati DFT proračuna su pokazali da je Ag+ jon jače vezan u Ca1 položaju (-1352,6 kcal/mol) nego u Ca2 položaju (-1249.0 kcal/mol). Ispitivanja antibakterijskih aktivnosti su pokazale da svi uzorci AgFAP imaju biocidni efekat na patogene, [1] dok samo AgFAP3 uzorak (1% Ag+) može poslužiti kao nanomaterijala za zaštitu od zračenja, kao i za pripremu fotoluminiscentnih dozimetara, jer ovaj materijal apsorbuje fotone u celoj oblasti UV zračenja. Rezultati ove studije ukazuju da su srebrom dopirani fluorapatitni nanomaterijali pogodni za različite biomedicinske primene, kao antibakterijski biomaterijali u ortopediji, stomatologiji i u prečišćavanje otpadnih voda.

Silver doped fluorapatite (AgFAP) nanopowders were synthesised by neutralization method (reaction of dissolving Ag2O in solution of HF and H3PO4 with suspension of Ca(OH)2). [1] AgFAP samples were synthesized with atomic ratios of [Ag/(Ag + Ca)]·100% of 0.001, 0.01 and 1%. The XRD patterns of FAP and Ag+-doped FAP samples (Figure 1) are similar, with the positions of X-ray diffraction peaks in accordance with ASTM data for fluorapatite. FAP as material has a crystal lattice with a hexagonal symmetry space group P63/m, with two structurally different positions of Ca2+ ion (Ca1 (4f) and Ca2 (6h) sites). FTIR and SEM analysis showed that the particles of AgFAP samples are nano-sized and homogenous. Fluorescence of AgFAP is red shifted to the green region compared to fluorescence of FAP nanoparticles (in the violet region of visible part of the spectrum). MCR-ALS analyses showed the formation of two maxima in AgFAP fluorescence spectra (at 420 and 520 nm), as a consequence of Ag+ ions doping at Ca1 (4f) site in the FAP lattice (Figure 1). The results of DFT calculations showed that an Ag+ ion is stronger bonded to Ca1 site (-1352.6 kcal/mol) than to Ca2 site (-1249.0 kcal/mol). Antibacterial studies have shown that all studied AgFAP samples exhibit biocidal effect against pathogens, [1] while only AgFAP3 (1% of Ag+) nanopowder might be used as the radiation protective nanomaterial, as well as for preparation of photoluminescence dosimeters, because this material absorbs photons over all part of the UV radiation spectrum. The result of this study indicates that Ag-doped fluorapatite nanomaterials are promising for different biomedical applications, as antibacterial biomaterials in orthopedics, dentistry and in the purification of waste water.