Embedding carbon dots and gold nanoclusters in metal-organic frameworks for ratiometric fluorescence detection of Cu2+

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Herein, a dual-emission metal-organic framework based ratiometric fluorescence nanoprobe was reported for detecting copper(II) ions. In particular, carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into ZIF-8 (one of the classical metal-organic frameworks) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at UV excitation. In the presence of Cu2+, the fluorescence attributed to AuNCs can be rapidly quenched, while the fluorescence of CDs serves as reference with undetectable changes. Therefore, the CDs/AuNCs@ZIF-8 nanocomposites were utilized as a ratiometric fluorescence nanoprobe for sensitive and selective detection of Cu2+. A good linear relationship between the ratiometric fluorescence signal of CDs/AuNCs@ZIF-8 and Cu2+ concentration was obtained in the range of 10−3–103 μM, and the detection limit was as low as 0.3324 nM. The current ratiometric fluorescence nanoprobe showed promising prospects in cost-effective and rapid determination of Cu2+ ions with good sensitivity and selectivity. Furthermore, this nanoprobe has been successfully applied for the quantitative detection of Cu2+ in serum samples, indicating its value of practical application.

Carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into metal-organic frameworks (ZIF-8) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at 365 nm excitation. In the presence of Cu2+, the fluorescence emission peak at 574 nm can rapidly respond by quenching, while the fluorescence at 462 nm serves as reference with undetectable changes.

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Correspondence to Fengli Qu or Limin Lu.

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Ethical committee approval

The human serum sample experiments were performed in strict accordance with the guidelines from the Ethical Committee, Qufu Normal University. All serum samples were obtained from healthy college student volunteers with their informed consent. All studies were approved by the Ethical Committee of Qufu Normal University.

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Tan, Q., Zhang, R., Zhang, G. et al. Embedding carbon dots and gold nanoclusters in metal-organic frameworks for ratiometric fluorescence detection of Cu2+. Anal Bioanal Chem (2020).

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  • Metal-organic frameworks
  • Ratiometric fluorescence nanoprobe
  • Copper
  • Carbon dots
  • Gold nanoclusters