Poly-L-lactic is one of the most widely used bio-based, biodegradable polyesters. It comes in high and low molar mass forms, the first characterized by poor adhesion due to cracking caused by high degree of crystallinity . Therefore low molar mass forms are preferred. The polymer is strongly hydrophobic and can therefore limit the adhesion of foulants. PLLA coating resulted in increased capacitance of the system, but well developed peaks with pH dependent position (~50 mV/dec) were clearly visible(Figure ). Coating allowed to detected syringaldazine signals even after 3 weeks of incubation in cell culture medium.