New nanosensor fabricated on single nanopore electrode filled with prussian blue and graphene quantum dots coated by polypyrrole for hydrogen peroxide sensing

Hydrogen peroxide (H 2 O 2 ) is a common oxidant that plays an important role in many biological processes and is also an important medium analysis in various fields. In this work, a new electrochemical nanosensor capable of detecting and quantifying hydrogen peroxide was introduced. This nanosensor was fabricated by electrodepositing prussian blue (PB)/graphene quantum dots (GQDs)/polypyrrole (PPy) on single nanopore electrode etched from single gold nanoelectrode. This prepapred nanosensor exhibits good electrochemical response to hydrogen peroxide with high sensitivity and stability, with a linear response in the 2.0 and 80 μM by using amperometric method and differential pulse voltammetry (DPV) method. The limit of detections are 0.33 μM (S/N = 3) for amperometric method and 0.67 μM (S/N = 3) for differential pulse voltammetry (DPV) method, respectively. This nanosensor can be used for the determination of hydrogen peroxide in human urine, and can serve as a new electrochemical platform to monitor H 2 O 2 release from single living cells due to its small overal dimension and high sensitivity.