A novel electrochemical aptasensor for ultrasensitive detection of kanamycin based on MWCNTs-HMIMPF6 and nanoporous PtTi alloy

A novel aptasensor based on a novel composite film consisting of multi-walled carbon nanotubes (MWCNTs), ionic liquid (IL) of 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF6), and nanoporous PtTi (NP-PtTi) alloy was constructed for ultrasensitive detection of kanamycin. The NP-PtTi alloy was successfully fabricated by a simple dealloying of PtTiAl source alloy in HCl solution. The NP-PtTi alloy has uniform interconnected network structure with specific surface area and was used to immobilize aptamer. After modified with the composite material, current signal was amplified obviously, which attributed to the larger specific surface area and excellent electrical conductivity of NP-PtTi and MWCNTs. A number of factors affecting the activity of the aptasensor have been discussed and optimized. Under the optimized conditions, the proposed aptasensor provided a linear range of 0.05-100 ng mL−1 with a low detection limit of 3.7 pg mL−1. This aptasensor displayed high sensitivity, stability and reproducibility. In addition, the as-prepared aptasensor was successfully used for the determination of kanamycin in a real sample.