Are compared and studied the structure and physical properties of microporous films based on cellulose nitrate produced using various processing methods for their use as carriers (substrates) bioactive composites (biosensors). Studied the adsorption mode in the front movement mechanism and filtering by pressure gradient protein solution (bovine serum albumin – BSA) on porous films made of cellulose nitrate. The estimation of the contribution of the diffusion component of protein transport process to the surface of the polymer matrix. The amount of adsorbed protein is determined by reducing the concentration of albumin in the original solution. With regard to the regime of the front filter modified Langmuir adsorption isotherm equation. The dependence of the limits of albumin adsorption on porous cellulose nitrate from the nominal pore size. It is shown that the characteristics of the porous film of cellulose nitrate can be used as carriers for the creation of biosensors based on composite materials, and as materials for microfiltration purification of protein solutions.