纸上荧光数码成像法快速测定花生壳中的木犀草素含量

Rapid Quantification of Luteolin in Peanut Shells by Fluorescence Digital Imaging of Reactions Spotted on Filter Paper

摘要:

本文利用木犀草素在乙二胺四乙酸二钠（EDTA）协同配合下可增强铽离子（Tb3+）荧光强度的特征，建立了一种快速测定木犀草素含量的纸上荧光数码成像法。将木犀草素溶液及EDTA、Tb3+、NaOH等检测试剂点样于纸芯片的检测区，用智能手机在紫外灯下采集并读取荧光图片的红（R）、绿（G）、蓝（B）颜色数值，研究了该检测体系的显色条件、干扰物质、木犀草素浓度计算模型等。结果表明：优化后的显色条件为依次在纸芯片检测区加入0.4 μL 1.0 mol/L NaOH溶液、1.0 μL 1.0×10-2 mol/L EDTA溶液、6 μL木犀草素标准溶液、0.75 μL 1.5 mmol/L Tb3+溶液，室温下反应5 min。在此条件下，木犀草素的浓度在0.05~4.0 mmol/L时与B/（R+G+B）成良好的线性关系，R2=0.9954；用该法测定花生壳中木犀草素含量时，回收率为96.5%~106.3%，相对标准偏差为3.9%。该法快速、简便、成本低廉，能用于复杂样品中木犀草素含量的现场测定。

Abstract:

A rapid luteolin quantification method based on fluorescence imaging of reagents spotted on filter paper was established in this study. The method was based on the ability of luteolin to significantly enhance the fluorescence intensity of Tb3+ in the presence of EDTA. Luteolin solution and detection reagent (including EDTA,Tb3+,NaOH) were spotted onto a paper chip, then red (R), green (G), and blue (B) fluorescence intensities were captured and read under UV light using a smartphone. Image exposure conditions, interfering substances, and luteolin concentration calculation methods were examined using this quantification system. Optimal fluorescence development conditions were as follows: add sequentially 0.4 μL1.0 mol/L NaOH solution, 1.0 μL 1.0×10-2 mol/L EDTA solution, 6 μL luteolin solution, and 0.75 μL 1.5 mmol/L Tb3+solution to the paper chip, then allow reaction to proceed for 5 min at room temperature. Under these conditions, luteolin will have a good linear relationship with B/(R+G+B) at concentrations between 0.05 and 4.0 mmol/L, R2=0.9954. When using this rapid quantification method to detect the luteolin content in peanut shells, recovery rates were between 96.5% and 106.3%, with a relative standard deviation of 3.9%. This method was rapid, simple, and economical, and allowed on-the-spot quantification of luteolin in complex samples.