Cranberry Beans Derived Carbon Dots as a PotentialFluorescence Sensor for Selective Detection of Fe3+ Ionsin Aqueous Solution

摘要

Recently, synthesis, characterization, and application of carbon dots have received much attention. Natural products are the effectual carbon precursors to synthesize carbon dots with fascinating chemical and physical properties. In this study, the fluorescent sensor of carbon dots derived from cranberry beans without any functionalization and modification was developed. The carbon dots were prepared with a cheap, facile, and green carbon precursor through a hydrothermal treatment method. The synthetic process was toxic chemical-free, convenient, and environmentally friendly. To find the optimized synthetic conditions, the temperature, heating time duration, and carbon precursor weight were evaluated. The prepared carbon dots were characterized by UV light, transmission electron microscopy, Raman, Fourier transform infrared, UV–vis, and fluorescence spectroscopy. The resulting carbon dots exhibit stable fluorescence with a quantum yield of approximately 10.85%. The carbon dots emitted the broad fluorescence emission range between 410 and 540 nm by changing the excitation wavelength and were used for thedetection of Fe³⁺ ions at the excitation of 380 nm. Itis found that Fe³⁺ ions induced the fluorescence intensityquenching of the carbon dots stronger than other heavy metals andthe Fe³⁺ ion detection can be achieved within 3 min. Spectroscopicdata showed that the obtained carbon dots can detect Fe³⁺ ions within the wide concentration range of 30–600 μMwith 9.55 μM detection limit.