The fluorescent CuNCs/ZIF-8 nanocomposites were facilely prepared by mixing the PEI protected CuNCs with the precursors of ZIF-8, and characterized by UV–vis absorption, fluorescence, FT-IR, TEM, XRD and XPS. The quantum yield of the CuNCs/ZIF-8 is 15 times that of the PEI-CuNCs. Furthermore, the CuNCs/ZIF-8 possesses better stability and higher fluorescence response due to protective and confinement effects of MOFs. It was found that H₂O₂ could cause much more quenching of fluorescent CuNCs/ZIF-8 than that of PEI-CuNCs, which might result from enriching H₂O₂ by ZIF-8. The CuNCs/ZIF-8 can be designed as a fluorescence probe to selectively and sensitively detect H₂O₂ with a linear range from 0.01 to 1.5 µM and a LOD of 0.01 µM, while those with PEI-CuNCs are 0.5–30 µM and 0.50 µM, respectively. Through formation of CuNCs/ZIF-8 hybrid, the sensitivity for the detection of H₂O₂ increases by nearly 50-fold, which makes CuNCs/ZIF-8 a desirable probe to detect H₂O₂ content in human serum samples. Also, we successfully demonstrated the potential application of the CuNCs/ZIF-8 for screening and evaluating activities of oxidase using glucose oxidase as a model. The glucose oxidase activity can be detected in a range of 0.1–10 mU/L with a LOD of 0.1 mU/L.

通过将PEI保护的CuNCs与ZIF-8的前体混合，可以轻松制备荧光CuNCs / ZIF-8纳米复合材料，并具有紫外可见吸收，荧光，FT-IR，TEM，XRD和XPS表征。CuNCs / ZIF-8的量子产率是PEI-CuNCs的15倍。此外，由于MOF的保护和限制作用，CuNCs / ZIF-8具有更好的稳定性和更高的荧光响应。已经发现，与PEI-CuNCs相比，H ₂ O ₂可以引起更多的荧光CuNCs / ZIF-8猝灭，这可能是由于ZIF-8富集了H ₂ O ₂所致。可将CuNCs / ZIF-8设计为荧光探针，以选择性和灵敏地检测H ₂ O ₂线性范围为0.01至1.5 µM，LOD为0.01 µM，而带有PEI-CuNC的LOD分别为0.5–30 µM和0.50 µM。通过形成CuNCs / ZIF-8杂交体，检测H ₂ O ₂的灵敏度提高了近50倍，这使CuNCs / ZIF-8成为检测人血清样品中H ₂ O ₂含量的理想探针。同样，我们成功地证明了使用葡萄糖氧化酶作为模型，CuNCs / ZIF-8在筛选和评估氧化酶活性方面的潜在应用。可以在0.1–10 mU / L的范围内检测到葡萄糖氧化酶的活性，其LOD为0.1 mU / L。