Stochastic electrochemistry for catalysis and analysis of carboneous bio-electrodes.

Descrizione del progetto

Migliorare il trasferimento di elettroni nelle celle a combustibile enzimatiche

Le celle enzimatiche a biocombustibile sono un esempio importante di una tecnologia in rapido sviluppo definita BES (sistemi bioelettrochimici) finalizzata alla creazione di elettricità. Prima di poter commercializzare BES è necessario superare una sfida, ossia migliorare il trasferimento di elettroni tra gli elettrodi e gli enzimi che crescono intorno a loro. A tal fine, il progetto STOCHELEC, finanziato dall’UE, sintetizzerà elettrodi basati su nanopunti di carbonio; tali nanostrutture possono essere progettate per abbinare i livelli di energia degli enzimi attivi di ossido-riduzione e potenziare la loro stabilità ed efficienza. Il miglioramento dell’accoppiamento elettronico tra la superficie dell’elettrodo e i catalizzatori enzimatici porterà a una maggiore produzione di elettricità.

Obiettivo

Bio-electrochemical sciences are essential for the development of biosensor and biofuels cells. The precise nano-structuration of conductive materials with electro-active enzymes allows the reversible transduction of electrical energy to chemical energy via direct electron transfer (DET). The operational stability of bio-electrocatalytic systems is limited by the constant and strong electrical field building-up at the interface. The electrode polarisation generates a strong and static electrical field rigidifying the interfacial electronic double layer, often preventing free enzymes’ dynamics and leading to an enzymes’ loss of activity due to the destruction of their active 3D structure. Customized electrical polarisation patterns have the potential to enhance both electro-enzyme stability and efficiency. Biological electronic transfers processes being non-linear, it is expected that electrical stochastic signal excitation can greatly influence the electron transfer process at a bio-electrode.

This proposal focusses on gaining new knowledge about the electronic stochastic and unambiguous stimulation of bio-electrodes for catalytic and analytical purposes. The first objective is to synthesize nanostructured carbon nano-dots (C-dots) electrodes for the immobilisation of redox enzymes. C-dots possess a so-called trap-state; an energetic level that can be engineered to match biological redox cofactor potentials and thus enhance electronic coupling between the electrode and redox active enzymes. The second aim is to investigate pulsed and alternative current polarisation for enhancing bio-electrocatalysts efficiency and electro enzymes’ stability with non-ambiguous electrical waveform. The third aim of this proposal is to develop a novel electro-analytical technique relying on the Fourier transform analysis of chronoamperometry signals stimulated by a stochastic signal polarisation of bio-electrodes (FTSC).