by introducing specific recognition groups while significantly improving their optical properties and biocompatibility. [15,16] Surface modification has emerged as a powerful strategy for optimizing the performance of CDs and regulating the surface state.Morin as a polyhydroxy flavonoid is widely found in daily foods and thus is ingested to supplement the body. It exerts a variety of beneficial effects in the body, including scavenging free radicals, fighting inflammation, and protecting nerves, and even has a blocking effect on the growth and proliferation of cancer cells. It is commonly used in clinical practice to treat stomach diseases, chronic inflammatory diseases, coronary heart diseases and cancer. [17][18][19][20] However, studies have shown that high doses of morin can lead to pro-oxidative effects on cells, affecting the absorption of substances, drug metabolism and even DNA damage. On the other hand, heavy metal Al 3+ is an important component often used in food packaging, paper, and pharmaceutical industries. [21][22][23][24] According to the World Health Organization study, the tolerable intake of Al 3+ in the human body is estimated to be less than 4 mg per day. [25] The long-term accumulation of excessive Al 3+ can lead to kidney failure and pose a serious threat to the bones, brain and nervous system. In view of the above, a series of analytical methods have been established for the detection of morin and Al 3+ , including high performance liquid chromatography, electrochemical analysis and gas chromatography. [26,27] The above methods have limitations such as complicated pre-treatment, expensive and difficult operation, while the fluorescence method can overcome the defects of existing methods and establish a simple, rapid and reliable detection method with far-reaching practical application prospects.Based on the above, novel cyan Z-CDs were synthesized by surface modification of CDs through amidation reaction using β-CD (Scheme 1). In particularly, β-CD increased the spatial site resistance between CDs, which effectively suppressed the aggregation quenching effect and improved the luminescence intensity, and this results in excellent dispersion, stability and superior fluorescence properties of Z-CDs. Furthermore, the addition of morin could effectively quenched the fluorescence of Z-CDs and Al 3+ could make rapid recovery of the fluorescence of the Z-CDs-morin. The spectral characterization and Carbon dots (CDs) are emerging photoluminescent materials with excellent optical properties. However, the lack of active sites in primitive CDs has limited their development applications. Herein, functionalized carbon dots (Z-CDs) are successfully prepared by surface modification of CDs with mono (6-amino-6-deoxy) cyclodextrin (β-CD). The introduction of β-CD increases the spatial potential resistance between CDs, which effectively reduces the self-quenching effect. Moreover, the conjugated domains of Z-CDs are expanded, which improves the optical properties with a quantum yield of 48.74%. Z-CDs are ab...
