A droplet-based microfluidic synthesis approach for preparation of ficin capped gold nano clusters (AuNCs) was developed. Well dispersed AuNCs could be procured within 8 min. Upon excitation wavelength at 340 nm, the resultant AuNCs exhibited a strong blue fluorescence with the maximum emission at 450 nm. Due to the aggregation-induced “turn-off” fluorescence mechanism, the synthesized AuNCs as a fluorescent probe displayed high sensitivity and good selectivity for sensing ferric ions. The relative fluorescence intensity versus ferric ions concentration yielded a good linear calibration in the range of 10.0–1000.0 μM (R² = 0.998) and the limit of detection was 4.1 μM. Moreover, the possible mechanism for abated fluorescence intensity of AuNCs by adding ferric ions was discussed briefly. Further, the as-prepared fluorescent AuNCs was successfully applied for the detection of serum ferric ions. The results indicated that the droplet-based microfluidic synthesis system could provide a new way for the rapid preparation of AuNCs with good polydispersity and have potential as the sensing probes for the analysis of ferric ions in real biological samples.

开发了一种基于液滴的微流合成方法，用于制备带帽丝的金纳米簇（AuNCs）。分散良好的AuNC可以在8分钟内获得。在340nm处激发波长时，所得的AuNCs显示出强蓝色荧光，在450nm处具有最大发射。由于聚集诱导的“关闭”荧光机制，合成的AuNCs作为荧光探针显示出高的灵敏度和良好的选择性，可检测三价铁离子。相对荧光强度与三价铁离子的浓度在10.0-1000.0μM（R ²= 0.998），检出限为4.1μM。此外，简要讨论了通过添加三价铁离子减轻AuNCs荧光强度的可能机理。此外，所制备的荧光AuNCs已成功应用于血清铁离子的检测。结果表明，基于微滴的微流体合成系统可以为快速制备具有良好多分散性的AuNC提供新的途径，并具有作为实际生物样品中铁离子分析的传感探针的潜力。