PolyEnzIM main scope is to obtain cross-linked polyelectrolyte/enzyme architectures onto sand microparticle surfaces with potential application in water cleaning by sorption and static/dynamic catalytic degradation of organic dissolved pollutants. PolyEnzIM propose a new and innovative method for core-shell composite materials, environmental friendly, with high sorption capacity for organic pollutants (dyes, drugs, bisfenol A) and subsequent transformation of these in less toxic compounds, inert or complete degraded under the immobilized enzyme influence. The components: sand, polyelectrolytes (polycations/polyanions) and enzymes (catalase, laccase, and peroxidase) will be assembled by a new and innovative technique: one step deposition by direct precipitation of binary or ternary nonstoichiometric complex in-situ formed followed by subsequent cross-linking for organic shell stabilization around each sand particles. The core-shell sand/(polycation/enzyme) composites will contain a high number of functional groups for pollutants sorption and enough enzyme amounts for subsequent catalytic degradation of pollutant molecules. PolyEnzIM project aims to reduce the production costs by using inexpensive sand and time synthesis by one-step deposition of all components onto solid surface due the great adhesion properties of the used polyanions. Dissemination: 5 articles submitted to ISI journals, participation at 6 international/national conferences.