State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China.
National Health Commission Key Laboratory of Forensic Sciences (NKLF) and National Biosafety Evidence Foundation (NBEF), Bio-Evidence Sciences Academy, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China.
Mikrochim Acta. 2024 Sep 7;191(10):578. doi: 10.1007/s00604-024-06651-3.
Detecting dopamine (DA) in biological samples is vital to understand its crucial role in numerous physiological processes, such as motion, cognition, and reward stimulus. In this work, p-type graphene on sapphire, synthesized via chemical vapor deposition, serves as substrate for the preparation of p-type CuS films through solid-phase sulfurization. The optimized CuS/graphene heterostructure, prepared at 250 °C using a 15-nm copper film sulfurized for 2 h, exhibits superior electron transfer performance, ideal for electrochemical sensing. It is confirmed that the spontaneous charge transfer from graphene to CuS, higher Cu(II)/Cu(I) ratio (~ 0.8), and the presence of well-defined nanocrystalline structures with an average size of ~ 35 nm in CuS significantly contribute to the improved electron transfer of the heterostructure. The electrochemical sensor based on CuS/graphene heterostructure demonstrates remarkable sensitivity towards DA, with a detection limit as low as 100 fM and a dynamic range greater than 10 from 100 fM to 100 μM. Additionally, it exhibits excellent selectivity even in the presence of uric acid and ascorbic acid 100 times higher, alongside notable storage and measurement stability and repeatability. Impressively, the sensor also proves capable of detecting DA concentrations as low as 100 pM in rat serum, showcasing its potential for clinically relevant analytes and promising applications in sensitive, selective, reliable, and efficient point-of-care diagnostics.
在生物样本中检测多巴胺（DA）对于理解其在众多生理过程中的关键作用至关重要，如运动、认知和奖励刺激。在这项工作中，通过化学气相沉积合成的蓝宝石上的 p 型石墨烯被用作通过固相硫化制备 p 型 CuS 薄膜的基底。在 250°C 下使用 15nm 铜膜硫化 2 小时制备的优化的 CuS/石墨烯异质结表现出优异的电子转移性能，非常适合电化学传感。证实了石墨烯到 CuS 的自发电荷转移、更高的 Cu(II)/Cu(I) 比（0.8）以及存在具有35nm 平均尺寸的定义明确的纳米晶结构，这些都显著促进了异质结的电子转移。基于 CuS/石墨烯异质结的电化学传感器对 DA 表现出显著的灵敏度，检测限低至 100fM，动态范围从 100fM 到 100μM 大于 10。此外，即使存在尿酸和抗坏血酸 100 倍高，它也表现出出色的选择性，同时还具有显著的存储和测量稳定性和重复性。令人印象深刻的是，该传感器还能够检测大鼠血清中低至 100pM 的 DA 浓度，展示了其在临床相关分析物中的潜在应用以及在敏感、选择性、可靠和高效的即时诊断中的有前途的应用。
