Fast and simple measurement of vitamin B12 by using nitrogen and sulfur co doped carbon quantum dots

Here, a green, low-cost, simple method for the production of Nitrogen-Sulphur-co doped carbon quantum dots via a one-step hydrothermal .Pomegranate juice was used as a source of carbon while cystamine as a source of sulfur and nitrogen. The carbon quantum dots were characterized by using X transmission electron microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FT-IR ). The carbon quantum dots were used as a fluorescence sensor for selective and sensitive determination of vitamin B 12. Briefly, the fluorescence intensity of carbon-doped was quenched in the presence of vitamin B12. The decrease in fluorescence intensity allowed for the analysis of vitamin B12 with satisfactory limit of detection and linear dynamic rang. The Stern- Valmer plot shows a linear relationship (R2 = 0.99) between F0 / F and vitamin B12 concentration in the range of 0 to 110 μM. The detection limit (LOD) of M was 8.2 10-8. Also, to evaluate the ability of this method for the analysis of real samples, vitamin B12 ampoule of Iranian Hormone Pharmaceuticals was selected as the real sample. High recoveries of the analysis these real samples prove the applicability of this method.