Lysozyme-enhanced europium(III)-metacycline luminescence and its application to the determination of metacycline.
A new spectrofluorometric method is described for the determination of metacycline (MC), based on modified enzyme-amplified lanthanide luminescence. Under the optimum conditions, Eu3+-MC forms a ternary complex with lysozyme in close proximity. Then lysozyme can remarkably enhance the characteristic fluorescence intensity of Eu3+ at 612 nm in metacycline-Eu3+ binary complex. The enhanced fluorescence intensity is in proportion to the concentration of MC. The limit of detection is 1.6 x 10(-8) mol L(-1), with a linear range from 6.2 x 10(-6) to 1.7 x 10(-5) mol L(-1). Interferences of other coexisting substances were studied. The developed method was successfully applied to the determination of MC in serum and urine samples. The mechanism of fluorescence enhancement was also studied.
Zhang
Na
N
Department of Chemistry, Shandong Normal University, Jinan, 250014, China.
Liu
Jin-Kai
JK
Jiang
Chong-Qiu
CQ
D005063:Europium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D049449:Luminescence; D008690:Methacycline / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry*; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D007202:Indicators and Reagents; D005063:Europium; D009113:Muramidase; D008690:Methacycline