Synergistic nanocomposites of gold nanorods and reduced graphene oxide for optical and electrochemical sensing of hydrogen peroxide

Hydrogen peroxide (H 2 O 2 ) plays important roles in biological and industrial processes, making its reliable detection essential. But its excessive levels pose health and ecological risks, necessitating sensitive detection methods. The present study presents synthesis and characterization of gold nanorods (AuNRs) and their reduced graphene oxide (RGO) nanocomposites as a dual optical–electrochemical platform for H₂O₂ sensing. AuNRs show a clear LSPR response with an optical detection limit of ∼18 µM, while integrating them with RGO greatly enhances electrochemical performance through improved charge transfer and structural stability. The electrochemical studies identify RGO-AuNRs electrode delivery for a broad linear range (17 nM–1 mM) with almost 3 times enhancement in sensitivity compared to AuNRs alone which shows only lower detection limit for H 2 O 2 sensing. The combined optical and electrochemical behavior, together with improved stability and cost-effective synthesis, demonstrates the advantage of this hybrid material and highlights its potential for practical biosensing applications. • AuNR and AuNR–RGO nanosensors enable dual optical/electrochemical H₂O₂ sensing. • AuNRs offer LSPR-based optical detection (∼18 µM) • RGO–AuNRs boost electrochemical response, Electrochemical range: 17 nM–1 mM; detection limit: 26 µM. • Synergistic AuNR–RGO yields a stable, low-cost platform for advanced biosensing