Facile one-pot synthesis of polyethyleneimine functionalized graphene for highly sensitive and selective electrochemical impedance aptasensing of kanamycin in serum
A facile one-pot synthesis method of polyethyleneimine functionalized graphene (PEI-G) was raised by employing polyethyleneimine (PEI) as both the reductive and functionalized reagent to reduce and wrap the exfoliated graphene oxide (EGO) for maintain the single layer status of graphene without aggregation. Based on the fine conductivity of PEI-G and high selectivity of aptamer specially designed for kanamycin, a novel electrochemical impedance aptasensor for the highly sensitive and selective detection of kanamycin in serum was fabricated using PEI-G as electrode substrate to enhance the electrochemical signal and using aptamer as a biological recognition unit to promote the selectivity. After the specifically capture of kanamycin in sample, the proposed aptasensor exhibited fine line response for kanamycin within the range of 10 fM to 100 pM with a detection limit of 5.2 fM. Meanwhile, the proposed aptasernsor also displayed good reproducibility, stability and specificity and suitable for the trace kanamycin analysis in real serum sample. Therefore, this proposed electrochemical impedance aptasensing strategy open a new sight for the potential applications in clinical diagnostics of kanamycin.