Microwave-assisted synthesis of N-doped carbon quantum dots for detection of methyl orange in saffron

In this study, a simple one-step microwave synthesis of nitrogen-doped carbon quantum dots (NCQDs) was performed using succinic acid as a carbon and gallic acid as a nitrogen source. Different techniques such as fluorescence spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and zeta potential analyzer were used for the characterization of as-synthesized NCQDs. The chemical composition and morphological features are analyzed by XRD and XPS spectroscopy. According to TEM investigations, these QDs exhibit a narrow size distribution ranging from 2 to 10, with maximum distribution at 6 nm. The maximum fluorescence intensity (FL intensity) of NCQDs was obtained at an excitation wavelength of 340 nm. The synthesized NCQDs were used as an effective fluorescent probe for the detection of MO with a detection limit of 0.77 μM. Moreover, the synthesized NCQDs gave satisfactory results when used for the detection of MO in saffron samples, with a recovery range of 98.6–99.2%. This study confirms that N-doped carbon quantum dots can be used as a potential candidate for the detection of MO in saffron.