Gold nanoclusters-poly(9,9-dioctylfluorenyl-2,7-diyl) dots@zeolitic imidazolate framework-8 (ZIF-8) nanohybrid based probe for ratiometric analysis of dopamine

• Published in: Analytica chimica acta 2020-02, Vol.1098, p.102-109
• Main Authors: Shao, Kang, You, Jia, Ye, Shiyi, Gu, Danyu, Wang, Tao, Teng, Yuanjie, Shen, Zhenlu, Pan, Zaifa
• Format: Article
• Language: English
• Subjects: Dopamine; Gold nanocluster; poly(9,9-dioctylfluorenyl-2,7-diyl); Ratiometric; Zeolitic imidazolate framework
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2019.10.065

Ratiometric analysis of dopamine (DA) in complex biological system is urgently desired. In this work, a novel dual-emission fluorescence probe was fabricated by embedding both gold nanoclusters (AuNCs) and poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO) dots into zeolitic imidazolate framework-8 (ZIF-8) (abbreviated as ZIF-8@AuNCs-PFO) and applied to ratiometric analysis of DA. Remarkably, encapsulating AuNCs and PFO dots into ZIF-8 not only achieved an excellent aggregation induced emission (AIE) enhancement effect on AuNCs (5 times increase), but also brought about an unique DA-triggered asynchronous fluorescence changes of AuNCs and PFO dots. The as-prepared probe exhibited excellent performance toward DA in the concentrations range from 0.01 to 10000 μmol L−1 and good selectivity over interfering substances. The detection limit of DA was as low as 4.8 nmol L−1. Furthermore, good stability and practicability of the probe in human serum samples suggesting its great potential for diagnostic purposes. Moreover, the quenching mechanism of AuNCs was intensively studied and summarized as three synergistic processes: (i) electron transfer between AuNCs and DA; (ii) DA-triggered architecture change of ZIF-8; (iii) fluorescence resonance energy transfer (FRET) between AuNCs and polydopamine (PDA), which offered an important theory for ZIF-based fluorescent probes. [Display omitted] •A novel strategy of encapsulating dual nano-emitters into metal-organic framework (MOF) was proposed•A “two-in-one” ZiF-8 encapsulated gold clusters-polymer dots (ZiF-8@AuNC-PFO) probe was constructed.•The aggregation fluorescence enhancement and DA-triggered asynchronous fluorescence quenching were used.•The dual-emission probe achieved high selective and ratiometric sensing of DA.