Colorimetric determination of total protein content in serum based on the polydopamine/protein adsorption competition on microplates

We report a facile, low-cost and safe analytical method for estimation of total protein content, even in complex matrix like human serum, by exploiting the competition between proteins and polydopamine (PDA) for surface binding. The surface coating has been examined by using a microplate reader taking the advantage of the PDA absorbance in the visible region, obtaining new insights into the modelling of polydopamine deposition and polymer/protein adsorption competition. This is helpful for rational development of imprinted biosensors, and potentially offering a with broad applications ranging from diagnostic tools in medicine to food analysis. The isothermal adsorption of polydopamine on polystyrene surface of multi-well plate displays a Langmuir-shaped curve. It allows the determination of the parameters of polymer film formation useful for any analytical assay depending on the surface coating. Among these, the molecular imprinting and the optical and acoustic evanescent sensing.