Carbon quantum dot-based fluorometric nitrite assay by exploiting the oxidation of iron(II) to iron(III)

Abstract

The authors describe a simple and economical fluorescence method for the determination of nitrite by utilizing the fact that nitrite possesses strong oxidation in acidic solution and is capable to transform iron(II) into iron(III) ions. The latter quenches the fluorescence of carbon quantum dots (CQDs) based on the fluorescence static and dynamic quenching effect. The optimum reaction conditions and other analytical parameters are investigated to enhance the sensitivity of the method. At the excitation wavelength of 360 nm, this probe has a linear response in the 10 to 400 μM nitrite concentration range, with a correlation coefficient of R = 0.9958 (n = 3) and a detection limit of 0.48 μM. This method was successfully applied to the determination of nitrite in three different sausage samples and gave recoveries in the range between 101.8 to 103.0%, demonstrating the accuracy, reliability and potential application of this assay for monitoring nitrite. Graphical Abstract The carbon quantum dot/iron(II) ions system was used for the fluorometric detection of nitrite in food and environmental water. This probe exploits the oxidizing property of nitrite in acidic solution. Iron(II) is oxidized to iron(III) which exerts a strong fluorescence quenching effect.

Ratiometric Fluorescence Determination of Trace Nitrite in Kimchi Based on Bsa-Templated Cu-Au Alloyed Nanoclusters (Bsa-Cuauncs)

“…To investigate the mechanism of quenching BSA-CuAuNCs by nitrite, rstly, XPS spectra of the system with and without nitrite were measured. It was possible that the oxidation of the core of BSA-CuAuNCs led to uorescence quenching due to oxidation capacity of nitrite (Liu et al 2018b). However, Cu2p and Au4f spectrum exhibited no obvious change, and the Cu2p spectra showed no a characteristic peak at 942 eV, indicating the absence of Cu ( ), which demonstrated that the uorescence quenching was not due to the oxidation of the metal core (Fig.…”

Cyanine dye-assembled composite upconversion nanoparticles for the sensing and cell imaging of nitrite based on a single particle imaging method

“…[4][5][6] Moreover, nitrite can also react with amines, proteins and other substances in the body to produce an n-nitrosamine substance in the stomach, which will lead to different cancers and severely damage the human nervous system. 7,8 Consequently, the exploring an easy method to detect the nitrite content is urgent.…”

Intrinsic Dual-Emitting Carbon Quantum-Dot-Based Selective Ratiometric Fluorescent Mercaptopurine Detection

“…For instance, there is no need for toxic solvents, expensive equipment, sophisticated sample preparation, and expert operators. 30,31 In spite of the vast effort, there is still a lack of accurate fluorometric sensors for many essential drugs. cence sensors have higher response stability and have been used widely for the detection of various drugs.…”

“…The fluorometric sensors based on CQDs have numerous advantages compared to the conventional detection methods such as Raman spectroscopy, electrophoresis, high-performance liquid chromatography (HPLC), and mass spectrometry. For instance, there is no need for toxic solvents, expensive equipment, sophisticated sample preparation, and expert operators. , In spite of the vast effort, there is still a lack of accurate fluorometric sensors for many essential drugs.…”