CaCl2作为异硫氰酸曙红固体基质室温磷光增强剂及其在免疫分析中的应用

有关荧光素的溴和碘取代物的低温磷光性质与取代度关系的研究表明，随着取代度的增大，磷光量子产率与荧光量子产率之比呈现先增大继而减小的趋势，即溴和碘的充分取代物的磷光反而减弱，故用eosin-ITC作标记物的报道很少．化学结构和环境等因素对磷光发射有重要影响；某些已被重原子(Br或／和I)高度取代的试剂，

Solid Substrate Room Temperature Phosphorescence of Eosin-5-isothiocynate and Application in Immune Analysis Using CaCl2 as an Enhancer

Room temperature phosphorescence(RTP) signal intensity of eosin-ITC on a polyamide membrane(PM) was very low, but the signal was increased obviously once some inorganic salts were added into the system at λex/λem=532 nm/685 nm. The enhancement effect of ⅡA element ions(such as Ca 2+, Sr 2+ and Ba 2+) on RTP of eosin-ITC is much obvious than that of Pb 2+ and Hg 2+ used constantly as an outer heavy atom perturber in phosphorimetry. Based on that, a new solid substrate room temperature phosphorescence immunoassay(SS-RTP-IA) for the determination of the human IgG was proposed to demonstrate the feasibility using eosin-ITC as phosphorescent marker. It was found that a good linear relationship with the ΔIP was obtained when the amount of human IgG in the range from 6.25 to 400 pg/spot(corresponding to the mass concentration: 15.63 ng/mL—1 μg/L, sample volume of 0.4 μL/spot). The regression equation of working curve can be expressed as ΔIP=3.062+0.00864x(pg)(n=7, r=0.996), The detection limit calculated as 3Sb/k is 0.394 pg/spot. The method was applied directly to the determination of IgG in human serum with a satisfying result. These results show that eosin-ITC can be used conveniently as a RTP marker of high sensitivity.