An electrochemical signal transduction amplification strategy for ultrasensitive detection of ascorbic acid

•A high sensitive electrochemical signal transduction amplification strategy was constructed for AA detection.•The AuNPs/MWNTs/PEI/GCE could also amplify the electrochemical signal dramatically.•This strategy could amplify the detection signal in about 107 times.•A detection limit as low as 15 fM was achieved with good selectivity.

A high sensitive electrochemical signal transduction amplification strategy was constructed based on the integration of the target-triggered silver deposition and the high sensitive stripping voltammetry detection. The Au-nanoparticles (AuNPs), multi-walled carbon nanotubes (MWNTs) and polyethyleneimine (PEI) modified glassy carbon electrode (AuNPs/MWNTs/PEI/GCE) was prepared and used as the working electrode which could also amplify the electrochemical signal dramatically due to the excellent electronic property of the electrode and the Au-nanoparticles induced silver deposition reaction. This strategy was applied to the high sensitive ascorbic acid (AA) determination and a detection limit as low as 15 fM was achieved, which was 6-9 orders of magnitude more sensitive than other reported methods for AA determination. The proposed method has good selectivity and anti-interference ability, which could be applied to AA detection in real complex samples.