A novel method to generate an integrated electrically contacted glucose dehydrogenase electrode by the surface reconstitution of the apo-enzyme on a pyrroloquinoline quinone (PQQ)-modified polyaniline is described. In situ electrochemical surface plasmon resonance (SPR) is used to characterize the bioelectrocatalytic functions of the system.

In this work, a previously undescribed phenomenon of orientation-induced redox isomerism in a Langmuir monolayer is revealed in the case of cerium bis-[tetra-(15-crown-5)-phthalocyaninate]-(Ce[(15C5)₄Pc]₂). It was established that intramolecular electron transfer (IET) from the electronic system of phthalocyanine to the 4f-orbital of cerium atom occurs upon spreading of a (Ce[(15C5)₄Pc]₂) chloroform solution onto the air–water interface (3D → 2D IET). This process is related to the transformation of Ce⁴⁺ cation in the solution to Ce³⁺ in the monolayer. It was also found that reversible Ce³⁺ ↔ Ce⁴⁺ IETs occur upon compression (π₁ → π₂) and expansion (π₂ → π₁) of monolayer (2D^π1 ↔ 2D^π2 IET, π-surface pressure). The mechanism of genuine redox isomerism was confirmed by the results of in situ UV–vis spectral measurements performed on monolayers and Langmuir–Blodgett films, AFM, and XPS studies of Langmuir–Blodgett films transferred at different surface pressures. The understanding of this reversible IET mechanism is especially important due to possible applications of such redox-isomeric systems in the development of nanoscale multibit information storage devices.