Electrochemical impedimetric aptasensors based on hyper-cross-linked porous organic frameworks for the determination of kanamycin

Abstract

A series of porous organic frameworks (POFs), namely POF-1, POF-2, and POF-3, has been successfully designed and constructed via a Friedel–Crafts reaction. By virtue of the outstretched π-conjugation structure, high surface area, and large pore cavity, these samples have the potential ability to load aptamer strands via strong π–π stacking interactions to fabricate electrochemical aptasensors. The label-free electrochemical aptasensor based on POF-3 can detect kanamycin ultra-sensitively with high selectively with a limit of detection of 0.0145 fg mL⁻¹ over a wide concentration range from 1.0 × 10⁻⁵ to 10.0 pg mL⁻¹via electrochemical impedance spectroscopy; meanwhile, the fabricated aptasensor reveals excellent selectivity in the presence of interferents at 1.0 × 10³ pg mL⁻¹, which is 1.0 × 10⁸ times higher than the concentration of kanamycin (1.0 × 10⁻⁵ pg mL⁻¹). Furthermore, the fabricated aptasensor can detect ultra-trace levels of kanamycin in real milk and human serum samples. As a result, this work exhibits a highly efficient approach for accurately detecting kanamycin.