Biosensor based on polyaniline–Prussian Blue/multi-walled carbon nanotubes hybrid composites

In this work, a novel route for fabrication polyaniline (PANI)–Prussian Blue (PB) hybrid composites is proposed by the spontaneous redox reaction in the FeCl3–K3[Fe(CN)6] and the aniline solution. With the introduction of multi-walled carbon nanotubes (MWNTs), the PANI–PB/MWNTs system shows synergy between the PANI–PB and MWNTs which amplified the H2O2 sensitivity greatly. A linear range from 8 × 10−8 to 1 × 10−5 M and a high sensitivity 508.18 μA μM cm2 for H2O2 detection are obtained. The composites also show good stability in neutral solution. A glucose biosensor was further constructed by immobilizing glucose oxidase (GOD) with Nafion and glutaraldehyde on the electrode surface. The performance factors influencing the resulted biosensor were studied in detail. The biosensor exhibits excellent response performance to glucose with the linear range from 1 to 11 mM and a detection limit of 0.01 mM. Furthermore, the biosensor shows rapid response, high sensitivity, good reproducibility, long-term stability and freedom of interference from other co-existing electroactive species.