| Metal-organic frameworks?MOFs?materials,as a kind of porous coordination polymer materials,are mainly constructed by metal ions or metal clusters and organic bridge ligands by self assembly mode.In recent years,the potential applications of MOFs materials have received widespread attentions.At present,various MOFs materials have been successfully used in numerous research fields,such as gas storage,chemical sensing,separation/adsorption,drug delivery,heterogeneous catalysis and biological imaging.MOFs materials possess many advantages including abundant active sites,good adsorption properties,adjustable pore structure,and excellent fluorescence properties,which make MOFs have a great application potential in the field of fluorescent sensing.Therefore,it is significant to develop MOFs as fluorescent sensor for analysis detection of target analytes in biological samples.In this paper,two kinds of MOFs materials with excellent fluorescence properties were synthesized under the solvo-thermal synthetic conditions,and then they was developed as fluorescent sensor to detect L-cysteine and folic acid in biological samples.The main contents are summarized as follows:?1?We synthesized a new{[Ca1.5??8-HL1??DMF?2]·DMF}n(CaII-MOFs;H4L1=1,1':4',1''-terphenyl-3,3'',5,5''-tetracarboxylic acid)material by solvo-thermal method.The CaII-MOFs material possessed many advantages including excellent fluorescence properties?FL quantum yields of 20.37%?,good chemical stability and great fluorescence stability.Then,the CaII-MOFs material was designed as an"off-on"mode fluorescent sensor for sensitive detection of L-cysteine in biological fluids.First,the fluorescence of CaII-MOFs was effectively quenched by Pb2+for providing a low fluorescence background.Whereafter,with addition of L-cysteine,the fluorescence of CaII-MOFs was gradually recovered.The fluorescence quenching mechanism was mainly due to static quenching caused by the interaction between Pb2+and CaII-MOFs to form a ground state complex.Additionally,the fluorescence recovery mechanism was mainly ascribed to Pb2+being released from CaII-MOFs/Pb2+hybrid system due to the interaction between L-cysteine and Pb2+.The proposed method could be applied for highly sensitive and selective detection of L-cysteine in human serum samples with satisfactory recoveries.?2?Awater-stablesilvermetal-organicframeworks{[Ag2??2-abtz???3-abtz??ClO4?]??ClO4?}n material?MOF-AgClO4-abtz;abtz=1-?4-aminobenzyl?-1,2,4,-triazole?was prepared,which exhibited a high fluorescent quantum yields of 78.97%,good water dispersibility and excellent chemical stability.Then,a''turn-off"fluorescent sensor was developed for sensitive detection of folic acid in biological samples via the inner filter effect?IFE?.The quenching mechanism was mainly ascribed to the spectrum overlap between fluorescence emission of MOF-AgClO4-abtz and the UV-vis absorption band of folic acid,then the fluorescence of MOF-AgClO4-abtz was absorbed by folic acid,resulting in fluorescence quenching.This detection method could effectively avoid the complex modification or functionalization process toward MOFs material,and could be directly employed for highly sensitive and selective detection of folic acid.Ultimately,this method was successfully applied for detection of folic acid in human serum and plasma with satisfactory recoveries. |
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