【摘要】 建立了以半导体聚合物聚[(9,9-二辛基芴)]量子点(PFO Pdots)为荧光探针的羧酸酯酶(Ca E)比率型荧光传感方法。带负电荷的PFO Pdots与带正电荷的聚乙烯亚胺(PEI)通过静电作用形成纳米复合物Pdots@PEI,在440和467 nm处有两个荧光发射峰。在Ca E作用下,Ca E的底物荧光素二乙酸酯(FDA)水解生成带负电的产物荧光素,此物质与带正电荷的Pdots@PEI之间由于静电作用距离拉近,两者可以发生共振能量转移,导致能量供体Pdots@PEI的荧光强度逐渐减弱,而荧光素的荧光强度逐渐增强。基于Pdots@PEI的荧光减弱和荧光素的荧光增强所构成的荧光强度比率关系,建立了选择性检测Ca E的新方法。在最优实验条件下,本方法对Ca E检测的线性范围为0.75~50.00 U/L,检出限为0.75 U/L(S/N=3)。将本方法用于兔血液中Ca E含量的检测,结果令人满意。更多还原

【Abstract】 A carboxylesterase( Ca E) ratiometric fluorescent probe based on semiconducting Poly( 9,9-dioctylfluorenyl-2,7-diyl)( PFO) polymer quantum dots( Pdots) was prepared. The negatively charged PFO Pdots and the positively charged polyethyleneimine( PEI) formed a nanocomposite Pdots @ PEI by electrostatic interaction,and emitted fluorescence at 440 nm and 467 nm. In the presence of Ca E,the substrate fluorescein diacetate( FDA) was hydrolyed into negatively charged fluorescein molecule,and could get closer to the positively charged Pdots@ PEI due to electrostatic interactions,which could induce resonance energy transfer,resulting in the energy donor Pdots@ PEI fluorescence intensity gradually weakened and the fluorescence intensity of the FDA hydrolysis product increased. Based on the fluorescence intensity ratio of Pdots@ PEI and the fluorescence enhancement of FDA hydrolysis products,a new method for selective detection of Ca E was established. Under the optimal conditions,the linear range of the method on Ca E testing was 0.75-50 U/L with detection limits of 0.75 U/L( S/N = 3). This method was used for the detection of the content of Ca E in rabbit blood with satisfactory results.更多还原