Abstract：
The practical and easy detection of dopamine levels in human fluids, such as urine and saliva, is of great interest due to the correlation of dopamine concentration with several diseases. In this work, the one-step synthesis of water-soluble carbon nanoparticles (CNPs), starting from artichoke extract, containing catechol groups, for the fluorescence sensing of dopamine is reported. Size, morphology, chemical composition and electronic structure of CNPs were elucidated by DLS, AFM, XPS, FT-IR, EDX and TEM analyses. Their optical properties were then explored by UV-vis and fluorescence measurements in water. The dopamine recognition properties of these CNPs were investigated in water through fluorescence measurements and we observed the progressive enhancement of the CNP emission intensity upon the progressive addition of dopamine, with a binding affinity value of log K = 5.76 and a detection limit of 0.81 nM. Selectivity towards dopamine was tested over other interfering analytes commonly present in human saliva. Finally, in order to perform a solid point of care test, CNPs were adsorbed on a solid support and exposed to different concentrations of dopamine, thus observing a pseudo-linear response, using a smartphone as a detector. Therefore, the detection of dopamine in simulated human saliva was performed with excellent results, in terms of selectivity and a detection limit of 100 pM.
摘要：
人体体液中多巴胺水平的实用和容易检测，比如尿液和唾液，由于多巴胺浓度与几种疾病的相关性，因此引起了极大的兴趣。在这项工作中,一步合成水溶性碳纳米颗粒(CNPs),从朝鲜蓟提取物开始，含有儿茶酚基团，据报道，多巴胺的荧光传感。尺寸,形态学,通过DLS阐明了CNPs的化学组成和电子结构，AFM,XPS,FT-IR,EDX和TEM分析。然后通过水中的UV-vis和荧光测量来探索它们的光学性质。通过荧光测量在水中研究了这些CNP的多巴胺识别特性，我们观察到在逐渐添加多巴胺时CNP发射强度的逐渐增强，结合亲和力值logK=5.76和检测限为0.81nM。相对于通常存在于人唾液中的其他干扰分析物,测试了对多巴胺的选择性。最后,为了进行可靠的护理点测试，CNPs吸附在固体支持物上，暴露于不同浓度的多巴胺，因此观察到伪线性响应，使用智能手机作为探测器。因此,模拟人唾液中多巴胺的检测结果优异，就选择性和100pM的检测限而言。
