基于碳点“开关”型荧光探针在组氨酸检测中的研究

研究并构建了一种基于荧光碳点(carbon dots,CDs)的新型"开关"探针,利用CDs荧光强度的变化进行痕量组氨酸(histidine,His)的检测。在pH 7.6的溶液中,钌(Ru)能与CDs通过静电吸引作用形成弱的基态化合物,导致CDs的荧光猝灭,此时体系处于"关闭"状态。而His与Ru有更强的亲和力,故向体系中加入His后,Ru从CDs表面竞争中下来,CDs的荧光得到恢复,此时体系被"打开"。考察了pH、缓冲溶液、反应时间、温度等因素对体系的影响,并初步讨论了Ru对CDs荧光的猝灭类型,得出了Ru对CDs荧光的猝灭属于静态猝灭的结论。实验结果表明,在pH 7.6的溶液中,在20~25℃条件下,体系在10min内反应完成。His的浓度与碳点荧光的恢复程度呈良好的线性关系,其线性范围为:6.5~219.3×10~(-6) mol·L~(-1),检出限为:2.15×10~(-6 )mol·L~(-1)。将方法应用于实际样品氨基酸注射液中组氨酸含量的测定,其RSD≤2.07%,回收率在95.7%~102.4%之间。将具有优良光学特性的CDs应用于构建"开关"型荧光探针,不但拓宽了CDs的应用范围,为一些重要物质的检测提供了参考。

Study of the Detection of Histidine Based on “On-Off” Fluorescence Probe of Carbon Dots

An new type of switch “On‐Off” fluorescence probe was constructed based on fluorescence carbon dots as a novel strategy to analyze trace histidine(His) which was proposed for the first time .In water solution with pH 7.6 ,the fluorescence of CDs was quenched with Ru3+ due to the formation of ground state compound through electrostatic attraction ,and the system was thus“turned‐off” .The fluorescence intensity of CDs was “turned‐on” due to the competition between His and Ru towards the surface of CDs .The effect of critical parameters including pH ,buffer solutions ,reaction temperature and time needed to grow the fluorescence intensity of CDs was studied .Results show thatin water solution with pH 7.6 ,and when the temperature was between 20~25 ℃ ,the fluorescence intensity of the released CDs displayed a linear relationship in the range of (6.5~219.3) × 10-6 mol · L -1 of captopril .Lower limit of detection for His ,at the signal‐to‐noise ratio of 3/(3δ) ,was 2.15 × 10-6 mol · L -1 .The methodology was successfully applied for the determination of His in Compound Amino Acid Injections ,with the RSD≤2.07% ,and the recovery rate was between 95.7% ~102.4% .The result of the experiment was satisfactory .On the one hand ,the excellent optical character CDs was acted as “On‐Off” fluorescence probe ,which could be extent the application of CDs ,on the other hand ,the excellent performance of the proposed fluorescence probe shows that this method possesses the po‐tential for practical application .