Copolymers and enzymes blended as LB films changing the bioelectronics properties of interfaces

This paper describes Langmuir monolayers of the polymer poly [(9,9-dioctylfluorene)-co-thiophene] (PDOF-co-Th) serving as matrix for urease incorporation and transferred to platinum supports as Langmuir-Blodgett films. The supramolecular structure forming highly organized films not only tuned the catalytic activity of urease, but also helped to prove the viability of the system to sensing urea as demonstrated with current-voltage and constant voltage measurements, exhibiting regular and distinctive output signals over all concentrations (from 1 x 10(-3) to 1.5 x 10(-2) mol/L) as demonstrated in this work. These results are related to the synergism between the compounds on the active layer, leading to a surface molecular arrangement which allowed fast analyte diffusion owing to an adequate molecular accommodation, taking advantage of the urease activity and of the properties of the polymer as molecular accommodator. This work then demonstrates the feasibility of employing LB films composed of copolymers and urease as electrochemical devices for biosensing applications as a proof-ofconcept experiment.