Graphene blended with SnO2 and Pd-Pt nanocages for sensitive non-enzymatic electrochemical detection of H2O2 released from living cells

Highlights: • Graphene blended with SnO₂ and PdPd nanocages composite was synthesized. • Pd-Pt nanocages and SnO₂/graphene nanosheets modified electrode (PdPt NCs@SGN/GCE) has high sensitivity for the determination of hydrogen peroxide (H₂O₂). • The constructed biosensor provided to be reliable for determination of H₂O₂ secreted from human cervical cancer cells (Hela cells). - Abstract: This paper described a novel, facile and nonenzymatic electrochemical biosensor to detect hydrogen peroxide (H₂O₂). The sensor was fabricated based on Pd-Pt nanocages and SnO₂/graphene nanosheets modified electrode (PdPt NCs@SGN/GCE). The electrochemical behavior of PdPt NCs@SGN/GCE exhibited excellent catalytic activity toward H₂O₂ with fast response, high selectivity, superior sensitivity, low detection limit of 0.3 µM and large linear range from 1 µM to 300 µM. Under these obvious advantages, the constructed biosensor provided to be reliable for determination of H₂O₂ secreted from human cervical cancer cells (Hela cells). Hence, the proposed biosensor is a promising candidate for detection of H₂O₂ in situ released from living cells in clinical diagnostics.