Fabrication and photoelectric response of poly(allylamine hydrochloride)/PM thin films by layer-by-layer deposition technique

Thin films of poly(allylamine hydrochloride) (PAH) and bacteriorhodopsin (bR) embedded in purple membrane (PM) have been prepared by layer-by-layer (LBL) self-assembly technique. The results obtained by UV–Vis spectroscopy and atomic force microscopy (AFM) analysis showed that the biological activity of bR was preserved and PM fragments could be well oriented onto the ITO substrate. A photo-electrochemical cell with the structure of ITO/(PAH/PM)n/electrolyte (0.5 M KCl)/Pt was fabricated and studied. The photocurrent peaks of (PAH/PM)6 corresponding to light-on and light-off were about 200 and 100 nA/cm2, respectively, with the former enhanced 30% higher than that of the reference films made of (PDAC/PM)6. [Copyright &y& Elsevier]