Evaluation of the nonbiofouling behaviour of nitric oxide electrochemical sensor materials by using sessile drop contact angle measurements and free enthalpy of adhesion calculations

In this study, we report the development of the concept of additivity of intramolecular forces at interfaces to calculate the free energy of adhesion of standard fouling agent models, namely human serum albumin (HSA), bovine serum albumin (BSA) and polyethyleneglycol (PEG) onto nitric oxide (NO) electrochemical sensor materials. This constitutes the first example of antibiofouling tendency evaluation of NO sensors, which may allow to predict their efficiency when used in complex biological systems. This was carried out by developing sessile drop contact angle measurements of three liquids of different polarity (water, glycerol and α-bromonaphtalene) onto the chemically modified sensor surfaces, and determining the free enthalpy of adhesion of the standard fouling agent models. Correlation between these calculations and experimentally determined sensitivities of the designed microsensors to NO in BSA-containing solution is also discussed.