Novel bimetallic Cu/Ni core-shell NPs and nitrogen doped GQDs composites applied in glucose in vitro detection

In present work, a highly sensitive biosensor with high selectivity for glucose monitoring is developed based on novel nano-composites of nitrogen doped graphene quantum dots (N-GQDs) and a novel bimetallic Cu/Ni core-shell nanoparticles (CSNPs) (Cu@Ni CSNPs/N-GQDs NCs). With the tuned electronic properties, N-GQDs helped bimetallic core-shell structure nanomaterials from aggregation, and separate the charges generated at the interface. This novel nano-composites also have the good electrical conductivity of N-GQDs, catalyst property of Cu/Ni bimetallic nano composite, Cu@Ni core-shell structure and the synergistic effect of the interaction between bimetallic nano composite and N-GQDs. While modified the electrode with this novel nano-composites, the sensor’ linear range is 0.09 ~ 1 mM, and the limit of detection (LOD) is 1.5 μM (S/N = 3) with a high sensitivity of 660 μA mM-1 cm-2, and rapid response time (3 s). Its’ LOD is more than 74 times lower than the traditional Cu@Ni CSNPs modified working electrode. It also has higher sensitivity and wider linear range. This indicates the great potential of applying this kind of nano composites in electrode modification.

本研究中，我们开发了一种用于葡萄糖检测的高灵敏度、高选择性生物传感器，其制备基于氮掺杂石墨烯量子点（nitrogen doped graphene quantum dots, N-GQDs）与新型双金属铜/镍核壳纳米颗粒（bimetallic Cu/Ni core-shell nanoparticles, CSNPs）构成的新型纳米复合物（Cu@Ni CSNPs/N-GQDs NCs）。通过调控电子特性，氮掺杂石墨烯量子点可抑制双金属核壳结构纳米材料的团聚，并分离界面处产生的电荷。该新型纳米复合物兼具氮掺杂石墨烯量子点的优良导电性、铜/镍双金属纳米复合物的催化活性、Cu@Ni核壳结构特性，以及双金属纳米复合物与氮掺杂石墨烯量子点间相互作用产生的协同效应。将该新型纳米复合物修饰于电极表面后，该传感器的线性范围为0.09~1 mM，检出限（limit of detection, LOD）为1.5 μM（信噪比S/N=3），灵敏度高达660 μA·mM⁻¹·cm⁻²，响应时间仅为3 s。其检出限较传统Cu@Ni核壳纳米颗粒修饰的工作电极低74倍以上，同时具备更高的灵敏度与更宽的线性范围。这表明该类纳米复合物在电极修饰领域具备极高的应用潜力。