Functionality of ZnPc Thin Film Deposited on Polystyrene Interlayer for Immobilization of Biomolecules in QCM Based Biosensor

Abstract

Functionality of zinc pthalocyanine (ZnPc) thin film for immobilization of biomolecules was studied using bovine serum albumin (BSA). The functionality is affected by microstructures and surface roughness of the film. This studies is conducted by producing ZnPc films by means of thermal evaporation in vacuum. The ZnPc films were deposited on quartz crystal substrates with a polystyrene interlayer. Observations were carried out using a scanning electron microscope and an optical micro-profilometry. Enhancement of the functionality is observed with the increase of the film thickness. Surface roughness and microstructures of the film influence the functionality in a complex way. Adsorbtion of the BSA molecules is associated with both the surface roughness and microstructures. Although generally the adsorption is proportional to the contact area but the roughness and fibrous microstructures of the deposited ZnPc produce complex adsorption and trapping mechanisms in the immobilization of the BSA.