Send to

Choose Destination
Nanoscale. 2018 Nov 7;10(41):19579-19585. doi: 10.1039/c8nr05767b. Epub 2018 Oct 16.

Fluorescent Ti3C2 MXene quantum dots for an alkaline phosphatase assay and embryonic stem cell identification based on the inner filter effect.

Author information

State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.


As an emerging two-dimensional material, MXenes have attracted much attention due to their unique physicochemical properties, but their application in biosensing has been lagging far behind because of their poor salt tolerance. Herein, a titanium carbide MXene quantum dot (Ti3C2 QD)-based fluorescent probe for the alkaline phosphatase (ALP) activity assay and embryonic stem cell (ESC) identification was developed by taking advantage of the inner filter effect (IFE). Ti3C2 QDs with ∼4.2 nm in diameter were prepared from Ti3C2 MXenes by hydrothermal treatment, exhibiting excellent salt tolerance, anti-photobleaching and dispersion stability in aqueous solution. Owing to the remarkable overlap between the absorption spectrum of p-nitrophenol (p-NP) and the excitation and emission spectrum of Ti3C2 QDs, p-NP generated from ALP-catalyzed dephosphorylation of the substrate, p-nitrophenyl phosphate (p-NPP), can effectively quench the fluorescence of Ti3C2 QDs through the IFE. As a result, sensitive fluorometric analysis of ALP activity was achieved without complicating the conventional colorimetric ALP detection system. The proposed assay was successfully applied to determine ALP activity with a low limit of detection (0.02 U L-1) as well as monitoring the enzyme activity in real time. Finally, accurate analysis of ALP, the biomarker of ESC, in ESC lysates was also achieved using this IFE-based method, affording an alternative method for ESC identification.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Royal Society of Chemistry
Loading ...
Support Center