Terminal protection of small molecule-linked ssDNA-SWNT nanoassembly for sensitive detection of small molecule and protein interaction

The interactions between small molecules and proteins constitute a critical regulatory mechanism in many fundamental biological processes. A novel biosensing strategy has been developed for sensitive and selective detection of small molecule and protein interaction on the basis of terminal protection of small molecule-linked ssDNA-SWNT nanoassembly. The developed strategy is demonstrated using folate and its binding protein folate receptor (FR) as a model case. The results reveal the developed technique displays superb resistance to non-specific binding, very low detection limit as low as subnanomolar, and a wide dynamic range from 100 pmol/L to 500 nmol/L of FR. Thus, it may offer a simple, cost-effective, highly selective and sensitive platform for homogeneous fluorescence detection of small molecule–protein interaction and related biochemical studies.

This strategy mainly relies on the binding event of a target protein to a small molecule-linked ssDNA-SWNT nanoassembly, which can efficiently protect the nanoassembly from the degradation by exonuclease. By incorporating a fluorophore in the small molecule-linked ssDNA, the small molecule–protein interaction can be readily probed by the fluorescent signals of the reaction system.Figure optionsDownload as PowerPoint slide