Background:
Morin has many pharmacological functions including antioxidant, anticancer,
anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection,
gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown
that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high
dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore,
it is necessary to determine the concentration of morin in biologic samples.
Method:
Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared
by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were
collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various
concentrations of morin.
Results:
The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction
and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly
with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear
response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed
fluorescent probe was applied to analysis of morin in human body fluids with recoveries of
98.0-102%.
Conclusion:
NSCDs were prepared by a microwave heating process. The present analytical method is
sensitive to morin. The quenching process between NSCDs and morin is attributed to the static
quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent
probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly
opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application
prospect.
Selective turn-on near-infrared fluorescence probe for hypoxic tumor cell imaging