Graphene Oxide and Conductive Polymer–Enhanced Langmuir–Blodgett Biosensor for Sensitive Detection of Pyrocatechol

In this work, we report a novel Langmuir-Blodgett (LB) biosensing platform for the detection of phenolic compounds, using Pyrocatechol as a model analyte. Although LB films have long been explored for polyphenol detection, the present study introduces an innovative hybrid architecture that integrates a lipid matrix (DMPA), a conductive polymer (P3HT), graphene oxide (GO), and laccase into a single, highly organized ultrathin film. This configuration simultaneously enhances film rigidity, reduces surface roughness, and modulates electron-transfer properties in a way not previously reported for LB-based enzymatic sensors. Comprehensive interfacial characterization (surface pressure-area isotherms, dilatational rheology, UV-Vis, AFM) reveals that GO plays a decisive role in promoting compact molecular packing and stabilizing the enzyme-polymer-lipid assembly. As a consequence, the resulting LB films exhibit significantly improved electrochemical performance, including nearly 2-fold higher sensitivity, lower detection limits, and reduced overpotentials compared with films lacking GO. The study also provides mechanistic evidence that the synergy between conductive polymer domains, GO nanosheets, and the immobilized enzyme facilitates more efficient redox cycling of Pyrocatechol. These findings demonstrate that the rational incorporation of GO into LB enzymatic architectures offers a promising route toward next-generation ultrathin biosensors with enhanced analytical performance and structural stability.