Immobilization of Laccase and Graphene Oxide in Langmuir–Blodgett Films as a Dual-Function Platform for Biosensors and Biosupercapacitors

The development of multifunctional hybrid films integrating biological and nanomaterial components offers promising avenues for advanced bioelectronic devices. In this study, we present Langmuir and Langmuir-Blodgett (LB) films composed of 1,2-dimyristoyl-<i>sn</i>-glycero-3-phosphate (DMPA), laccase (LAC), and graphene oxide (GO) as a versatile platform for both biosensing and energy storage applications. The films were thoroughly characterized using tensiometry, surface potential measurements, Brewster angle microscopy (BAM), and polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), revealing the successful incorporation of LAC and GO into DMPA monolayers without significant disruption of enzyme secondary structure. Enzymatic assays confirmed that LAC retained catalytic activity after immobilization, with GO enhancing both activity and diffusion dynamics. Electrochemical measurements demonstrated the films' capacitive behavior, with GO significantly improving current density and charge retention in cyclic voltammetry and galvanostatic charge-discharge experiments. Additionally, the films exhibited excellent structural stability and electrochemical performance across multiple cycles. These findings demonstrate the potential of DMPA + LAC + GO LB films as a dual-function platform for phenolic compound biosensing and biosupercapacitor applications, highlighting the synergy between biocatalytic activity and electrochemical performance enabled by this hybrid architecture.