槲皮素作为荧光探针对醋酸根离子的识别作用（英文）

A natural quercetin-based fluorescent sensor for sensitive and selective detection of acetate ions

为了探讨天然产物槲皮素作为荧光探针检测醋酸根离子的选择性和灵敏性,实验将不同种类阴离子加入到槲皮素的二甲亚砜溶液中,考查槲皮素溶液的荧光强度变化。实验发现:槲皮素的二甲亚砜溶液在500 nm处有一荧光发射峰,加入醋酸根离子时,该峰强度明显增强,而其他阴离子(Cl^-、Br^-、I^-、ClO^-_4、H_2PO^-_4)对该峰强度无明显影响,同时在Q-Ac^-中加入其他阴离子未引起荧光强度的变化。表明槲皮素对醋酸根离子具有较好的选择性;荧光滴定光谱表明槲皮素对醋酸根离子具有较高的灵敏度,且荧光滴定曲线线性关系较好(R^2=0995),线性范围为1.0×10^(-6)~8.0×10^(-6)mol/L,最低检测限为1.0×10^(-7)mol/L;通过Job曲线得到槲皮素与醋酸根离子作用的化学计量比为3∶2,稳定常数为3.11×10~4。核磁等实验表明,醋酸根离子的加入破坏或减弱了体系原有的氢键,促进了槲皮素分子内电荷转移,使槲皮素的荧光强度增强。用该方法检测了样品中微量的醋酸根离子,回收率为98.82%~100.96%,测定结果稳定。

A natural quercetin-based fluorescent sensor for sensitive and selective detection of acetate ions has been studied. Changes of fluorescence spectrum were studied before and after the addition of different anions in dimethyl sul-foxide （DMSO） solution of quercetin （Q）, fluorescence emission intensity of Q increased obviously, acetate ions en-hance fluorescence emission. And the fluorescence emission intensity had no change when adding other anions （ CI-, Br-, I-, ClO4-, H2PO4-）. All suggested that the progress for detecting acetate ions will not be affected by other anions, and quercetin-based fluorescent sensor has good selectivity. The sensor Q can be applied to the quantification of acetate ions with a linear range of 1.0×10^-6-8.0×10^-6 mol/L and the detection limit of 1.0 x 10-7 mol/L. The stoichiometric ratio of Q and acetate ions was 3：2 obtained by Job＇s plot. The stability constant is 3.11×10^4. The 1H-NMR spectra of Q and Q- Ac- system showed a probable mechanism of quercetin recognition was that Ac- could destroy or weaken original hydrogen bonds, and promote charge transfer within quercetin molecule, which resulted in fluorescence intensity increasing. This method had been successfully applied in detecting acetate ions of samples in DMSO with good recovery （98.82%-100. 96%） and repeatability.