Cyclodextrin Functionalized Carbon Dots Using IFE and FRET Dual Mechanism for Sequential Detection of Morin and Al³⁺

Abstract

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...

Novel β-cyclodextrin doped carbon dots for host–guest recognition-assisted sensing of isoniazid and cell imaging

“…The characteristic absorption peaks at 3400 cm −1 , 2920 cm −1 , 1640 cm −1 , 1400 cm −1 and 1040 cm −1 can be associated with the O–H, C–H, C O/C C, C–H, C–O groups respectively. 35,42 The only peak observed at 1730 cm −1 in the spectrum of CCDs-140 was the characteristic absorption of C O, 7 proving the participation of citric acid in the formation of CCDs. While the spectrum of CCDs-180 was very different from that of β-CD and CCDs, the results showed that the chemical structure of the carbon source changed significantly at high reaction temperature, further reaffirming our speculation that the functional groups, to a large extent, can be preserved under low reaction temperature.…”

“…In addition, CDs were always synthesized rst and then modied with b-CD to retain its recognition ability in previous studies, thus resulting in complicated preparation and purication processes. 29,[33][34][35] Therefore, the exploration of new methods of CDs preparation and b-CD modication to simplify the construction of new uorescence sensors is necessary.…”

Heteroatom-Doped Carbon Quantum Dots and Polymer Composite as Dual-Mode Nanoprobe for Fluorometric and Colorimetric Determination of Picric Acid

“…Additionally, this method was compared with other published literature methods regarding the determination of PA in terms of linear ranges, and LODs are listed in Table S3. Examination of Table S3 reveals that this fluorometric probe can yield a very low LOD and a reasonable range of linearity 42 To explore the current quenching mechanism of the proposed carbon dots-based fluorescence probe (ON−CDs), first, the optical properties (i.e., absorption spectra and fluorescence excitation/emission spectra of ON−CDs and ON−CDs + PA complex) were investigated. It has been well reported in the literature that the FRET process essentially occurs when the fluorescence emission spectra of the fluorophore overlap with the absorption spectra of the analyte or quencher.…”

The highly sensitive “turn-on” detection of morin using fluorescent nitrogen-doped carbon dots

“…Numerous CD sensing systems for morin mainly involved the fluorescence turn-off sensing principle. [19][20][21] Thus, the strong fluorescence signal background from probes may be one reason hampering the improvement in sensitivity. 22,23 Therefore, it would be noteworthy to prepare fluorescent CDs with a lighting-up behaviour for morin detection.…”