초록 |
Size-controllable aptamer conjugated ultrathin carboxylated polypyrrole nanotubes (A-UCPPyNTs) were fabricated as transducers in 17β-estradiol field-effect transistor (FET)-type biosensors. They were manufactured via a self-degradation method under several different conditions to control the diameter of the nanotubes. For targeting 17β-estradiol, the aptamers were immobilized through covalent bonding on its surface. The resulting biosensor demonstrated p-type behavior with outstanding electrical conductivity, and exhibited Ohmic contacts between the samples and electrodes. The smaller diameter (40 nm) of UCPPyNTs contributed to the biosensor’s enhanced performance by generating a larger surface area, thereby increasing the number of conjugated binding aptamers. In conclusion, the A-UCPPyNT FET-type biosensor showed extremely high sensitivity (~1 fM) toward 17β-estradiol, unique selectivity to the 17β-estradiol molecule, and outstanding reusability and long-term storage stability. |