Formation of multigradient porous surfaces for selective bacterial entrapment

Herein we describe the preparation of multigradient porous platforms by using the breath figures approach. In a single and straightforward step, we prepared porous surfaces in which three different parameters vary gradually from the edge of the sample to the center in a radial manner. Thus, we evidenced the gradual variation of the pore size and the shape of the pores that can be varied, depending on the sample concentration, but also depending on their radial position within the same sample. In addition, we succeeded in the control over the chemical composition inside and outside the pores as well as the variation of the concentration of block copolymer inside the pores as a function of their radial position. Moreover, the chemical composition and the variable cavity size of porous surfaces have been evaluated to analyze the influence of these variables on the selective bacterial immobilization. To the best of our knowledge this is the first example in which, by using a simple one-step strategy, a multigradient surface can be obtained. These initial results can be the base to construct platforms for selective immobilization and isolation of bacteria.