A novel electrochemical detection method for aptamer biosensors.
A beacon aptamer-based biosensor for the detection of thrombin was developed using electrochemical transduction method. Gold surface was modified with a beacon aptamer covalently linked at 5'-terminus with a linker containing a primary aliphatic amine. Methylene blue (MB) was intercalated into the beacon sequence, and used as an electrochemical marker. When the beacon aptamer immobilized on gold surface encounters thrombin, the hairpin forming beacon aptamer is conformationally changed to release the intercalated MB, resulting a decrease in electrical current intensity in voltamogram. The peak signal of the MB is clearly decreased by the binding of thrombin onto the beacon aptamer. The linear range of the signal was observed between 0 and 50.8 nM of thrombin with 0.999 correlation factor. This method was able to linearly and selectively detect thrombin with a detection limit of 11 nM.
Bang
Gyeong Sook
GS
School of Chemical and Biological Engineering and Institute of Molecular Biology and Genetics, Seoul National University, Kwanak-ku, South Korea.
Cho
Suhyeong
S
Kim
Byung-Gee
BG
D052157:Aptamers, Nucleotide / Q000032:analysis / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry*
D052157:Aptamers, Nucleotide; D020099:Coated Materials, Biocompatible; D013917:Thrombin