Horseradish peroxidase supported on porous graphene as a novel sensing platform for detection of hydrogen peroxide in living cells sensitively.

A viable and simple method for preparing porous graphene network using silver nanoparticles (AgNPs) etching was proposed, and a sensitive biosensor was constructed based on the porous graphene (PGN) and horseradish peroxidase (HRP) to measure the release of H ₂ O ₂ from living cells. Owing to the large surface area and versatile porous structure, the use of nanoporous materials can significantly improve the analysis performance of the biosensor by loading large amounts of enzyme and accelerating diffusion rate. Meanwhile, the constructed electrode exhibited excellent electrochemical performance toward H ₂ O ₂ with a determination limit as low as 0.0267nM and wide linear range of 7 orders of magnitude, which was superior to other H ₂ O ₂ electrochemical sensors. Thus, this novel biosensor can detect the H ₂ O ₂ release from living cells not only under normal physiological conditions (10 ^-8 -10 ^-7 M) but also in emergency state with the increased concentration (~10 ^-4 M). This work provides tremendous potential for real-time tracking of the secretion of H ₂ O ₂ in different types of physiological and pathological investigations.
(Copyright © 2016 Elsevier B.V. All rights reserved.)