基于碳点分子印迹纸芯片法测定金银花绿原酸含量

基于数码成像法，利用荧光碳点的高灵敏度结合分子印迹技术的高选择性，建立一种微流控纸芯片法并进行优化，用于金银花绿原酸含量的快速测定。以氮硫掺杂碳点为荧光响应材料，绿原酸为模板分子，在滤纸亲水区表面合成绿原酸印迹聚合物，制得碳点分子印迹纸芯片。以显色斑点的红、绿、蓝值为评价指标进行单因素优化试验。得到最佳制备条件：绿原酸、3-氨丙基三乙氧基硅烷（功能单体）、正硅酸乙酯（交联剂）的物质的量比1∶8∶8，每0.01 mmol绿原酸添加1 mL无水乙醇、0.2 mL氨基修饰的碳点溶液，预聚液超声辅助聚合时间35 min。最佳显色条件：点样量4 μL，显色时间15 min。在最优条件下测定金银花中绿原酸含量，绿原酸质量浓度在0.025～0.15 mg/mL时与绿值有较好的线性关系，决定系数为0.991 8，检出限为0.020 6 mg/mL，回收率在90.77%～102.10%之间。本实验建立的纸芯片法成本低廉、选择性良好且检测速度快（20 min内可完成），可作为测定条件简陋或现场临时快速测定绿原酸含量的补充方法。

Determination of Chlorogenic Acid in Honeysuckle by Carbon Dot-Molecularly Imprinted Paper Chip

Based on digital imaging, a microfluidic paper chip for the rapid determination of the chlorogenic acid content in honeysuckle was developed and optimized by using carbon dots, which combines the high accuracy of fluorescence carbon dots and the high selectivity of molecularly imprinted polymers. Using nitrogen and sulfur co-doped carbon dots as a fluorescent sensing material and chlorogenic acid as a template molecule, a carbon dot-molecularly imprinted paper chip was made by synthesizing molecularly imprinted polymers on the hydrophilic surface of filter paper. Based on the redness, greenness, and blueness values of colored spots, the experimental conditions were optimized using single-factor experiments. The optimal preparation conditions were molar ratio of chlorogenic acid to 3-aminopropyltriethoxysilane (functional monomer) to ethyl orthosilicate (cross-linking agent) 1:8:8, addition of 1 mL of anhydrous ethanol and 0.2 mL of amino-modified carbon dot solution to 0.01 mmol of chlorogenic acid, and ultrasound-assisted polymerization for 35 min. The optimal color development conditions were sample volume 4 μL, and reaction time 15 min. Under the optimized conditions, a good linear relationship was obtained between the greenness value and chlorogenic acid concentration in the range of 0.025–0.15 mg/mL, with a determination coefficient of 0.991 8, and the detection limit of the method 0.020 6 mg/mL. The recoveries of chlorogenic acid spiked into honeysuckle were 90.77%–102.10%. The paper chip method has the advantages of low cost, good selectivity and rapidity (It can be completed within 20 min). It can be used as a supplementary method for the determination of chlorogenic acid in the field or under primitive conditions.