Aptasensor for electrochemical sensing of angiogenin based on electrode modified by cationic polyelectrolyte-functionalized graphene/gold nanoparticles composites

•The sensor exhibited low detection limit (0.064 pM) and wide linear range to angiogenin (0.1 pM–5 nM).•The proposed electrochemical aptasensor is very simple, cost-effective, highly sensitive.•The sensor provides a promising strategy for the cancer diagnosis in medical application in the future.

Herein, a label-free and highly sensitive electrochemical aptasensor for the detection of angiogenin was proposed based on a conformational change of aptamer and amplification by poly(diallyldimethyl ammonium chloride) (PDDA)-functionalized graphene/gold nanoparticles (AuNPs) composites-modified electrode. PDDA-functionalized graphene (P-GR) nanosheets as the building block in the self-assembly of GR nanosheets/AuNPs heterostructure enhanced the electrochemical detection performance. The electrochemical aptasensor has an extraordinarily sensitive response to angiogenin in a linear range from 0.1 pM to 5 nM with a detection limit of 0.064 pM. The developed sensor provides a promising strategy for the cancer diagnosis in medical application in the future.