Nitrogen- and sulfur-doped carbon dots as peroxidase mimetics: colorimetric determination of hydrogen peroxide and glutathione, and fluorimetric determination of lead(II)
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Fluorescent carbon dots co-doped with nitrogen and sulfur (N/S CDs) were prepared and found to display viable peroxidase mimicking activity. They have a blue fluorescence (with excitation/emission maxima at 340/456 nm) with a quantum yield of 35%. The N/S CDs catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2, and this leads to the appearance of a blue solution with a absorption maximum at 654 nm. A colorimetric method was developed for the determination of H2O2 that has a 1.75 μM detection limit and a linear response in the 10−5 to 10−4 M concentration range. The method can be extended to the enzymatic determination of glutathione with a 0.26 μM detection limit and a working range from 0.20 to 100 μM. In addition, the CDs respond to lead(II) which is a quencher of the blue fluorescence at 456 nm, with a detection limit of 11 μM and a working range up to 100 μM. Simultaneously, the color changes can be visually detected with absorbance signal changes from 10 to 100 μM with limit of 3.9 μM. A multiple detection system was worked out that allows monitoring of H2O2 and glutathione successively, and of lead(II).
KeywordsCarbon quantum dots Nanoprobe Colorimetric Static quenching Catalyst Pb2 + Doping Hydrogen peroxide Detecting GSH
This work was supported by Heilongjiang Postdoctoral fund (LBH-Q17084), Heilongjiang Provincial Education Department (Project No. 12511141) and Harbin normal university (HSDSSCX2018-20).
Compliance with ethical standards
The author(s) declare that they have no competing interests.
- 25.Yan F, Zu F, Xu J, Zhou X, Bai Z, Ma C, Luo Y, Chen L (2019) Fluorescent carbon dots for ratiometric detection of curcumin and ferric ion based on inner filter effect, cell imaging and PVDF membrane fouling research of iron flocculants in wastewater treatment. Sensors Actuators B Chem 287:231–240CrossRefGoogle Scholar
- 30.Das P, Ganguly S, Maity PP, Bose M, Mondal S, Dhara S, Das AK, Banerjee S, Das NC (2018) Waste chimney oil to nanolights: a low cost chemosensor for tracer metal detection in practical field and its polymer composite for multidimensional activity. J Photochem Photobiol B Biol 180:56–67CrossRefGoogle Scholar
- 39.Iqbal A, Iqbal K, Xu L, Li B, Gong D, Liu X, Guo Y, Liu W, Qin W, Guo H (2018) Heterogeneous synthesis of nitrogen-doped carbon dots prepared via anhydrous citric acid and melamine for selective and sensitive turn on-off-on detection of hg (II), glutathione and its cellular imaging. Sensors Actuators B Chem 255:1130–1138CrossRefGoogle Scholar