【摘要】 利用高荧光效率的石墨烯量子点(GQDs)作为传感元件,设计组装GQDs脂肪酶活荧光传感器。当Hg2+存在时,Hg2+通过静电吸引作用吸附在GQDs表面,导致GQDs荧光被猝灭;加入脂肪酶及其底物巯基乙酸甲酯(MT),脂肪酶能够水解其底物生成巯基乙酸(TGA),TGA与Hg2+之间具有更强的结合力,从而使Hg2+从GQDs表面释放出来,GQDs的荧光又重新恢复,且荧光恢复强度与脂肪酶的活性有关,因此可以利用此荧光传感策略来定量检测脂肪酶活。在最优条件下,测得的脂肪酶检出线性范围为0.05~1.6 mg/m L,检出限为2.77×10-4 mg/m L。该方法还测定了另外四种商品化脂肪酶的活性,实验结果与恒电位滴定法测定结果一致,证明该方法具有良好的实用性。此外,与传统的比色法相比,该方法具有更高的灵敏度和选择性,简单方便且可用于高通量、实时检测脂肪酶活性。更多还原

【Abstract】 In this paper, with high fl uorescence effi ciency graphene quantum dots(GQDs) as sensing elements, GQDs’ lipase fl uorescence sensor was designed. When there is presence of Hg2+, Hg2+ could adsorb on the surface of GQDs by electrostatic attraction, which quenched the fl uorescence of GQDs; lipase and its substrate mercaptoacetic acid methyl ester(MT) were added, lipase could hydrolyze its substrate to generate thioglycolic acid(TGA), which resulted in a stronger binding force between TGA and Hg2+, so that Hg2+ released from the surface of GQDs. The fl uorescence of quenched GQDs was restored, and the intensity of fl uorescence recovery was related to the activity of lipase, so it can be used to quantitatively detect lipase activity. Under the optimal conditions, the linear range of the lipase is 0.05~1.6 mg/m L, and the detection limit is 2.77×10-4 mg/m L. The activity of the other four commercial lipases are determined by the method. The experimental results are consistent with the results of the titration assay. In addition, compared with the traditional colorimetric method, this method which is simple and convenient has higher sensitivity and selectivity, and can be used for high throughput and real-time detection of lipase activity.更多还原