A novel fluorescent probe for Fe3+ detection based on two-dimensional leaf-like structure CDs@ZIF-L

Abstract

A novel fluorescent composite (CDs@ZIF-L) was synthesized for the selective detection of Fe3+ based on the encapsulation of Carbon dots (CDs) into Zeolitic imidazolate frameworks (ZIF) with a two-dimensional leaf-like structure. The physicochemical structure, surface morphology, and composition of the adsorbent were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The results showed that unlike the conventional three-dimensional rhombic structure (ZIF-8), the synthesized two-dimensional leaf-like nanosheets (ZIF-L) not only maintained the structural integrity but also had a permeable pore structure. Importantly, at an excitation wavelength of 350 nm, the composite's had significant fluorescence emission at 445 nm and was effectively quenched in the presence of Fe3+, which can be used as an effective fluorescent scaling probe. Under the optimal conditions, CDs@ZIF-L was used as a fluorescent probe to detect Fe3+ with good linearity in the range of 0.02–2 mM (R2 = 0.9948) and a low detection limit of 0.891 μM. The fluorescent probe can also be used for the determination of Fe3+ in fruit samples with good recovery and accuracy, showing great potential for applications in environmental monitoring and agricultural pollutant control. It has good recovery and accuracy and shows great potential for environmental monitoring and agricultural pollutant control.