Photoluminescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

Novel Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state method in air.The structures of the samples were characterized by powder X-ray diffraction using Rietveld refinement to determine the occupation of crystal sites.The samples are found to have a centrosymmetric structure with space group R3c,as shown by dielectric measurements.These synthesized Ca_(8)CuRE(PO_(4))_(7)samples have multifunctional properties.The Cu^(2+)ions provide antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is biocompatible.The photoluminescence properties of RE^(3+)ions were studied and compared with other simmilar Ca_(8)MRE(PO_(4))_(7)phosphates,where M is a divalent metal.The photoluminescence intensity quenching in terms of energy transfer from RE^(3+)to Cu^(2+)is disscused.The bioactive properties were studied in relation to antibacterial activity against E.coli and S.aureus.All syntesized Ca_(8)CuRE(PO_(4))_(7)samples demonstrate very high and stable inhibition of bacteria growth.The correlation between crystal structure and properties is discussed.By combining multiple approaches to the directio nal design of such materials,several important properties within a single chemical compound to achieve biovisualization and bioactive properties simultaneously can be combined.