FRET-based aptamer probe for rapid angiogenin detection.

A sensitive method for rapid angiogenin (Ang) detection based on fluorescence resonance energy transfer (FRET) has been described. A dual-labeled probe based on high affinity aptamer for Ang was constructed. As donor and acceptor, 6-carboxyfluorescein (FAM) and 6-carboxy-tetramethylrhodamine (TMR) were labeled at 5'- and 3'-termini of the aptamer probe, respectively. The dual-labeled probe showed obvious fluorescence changes due to the specific binding between aptamer and Ang. By monitoring the fluorescence intensity of donor and acceptor, quantitative Ang detection could be achieved. This assay is highly specific and sensitive, with a detection limit of 2.0 x 10(-10) mol L(-1) and a linear range of 5.0 x 10(-10) to 4.0 x 10(-8) mol L(-1) Ang. Ang in serum samples of health and lung cancer were also detected.