Exposure to hazardous chemicals poses a constant threat and its impact on human health has prompted us to develop methods to decontaminate toxic chemical agents to provide protection against chemical agents and pesticides. Development of cost-effective, environmental benign, self-decontaminating substrates (particles, fibers and fabrics) is essential to meet the existing needs not only to absorb toxic chemicals upon encounter, but also release out non-toxic chemicals as a result of decontamination. OPH enzyme bearing polymeric assemblies were demonstrated to maintain hydrolytic activity against a pesticide, methyl parathion (MPT), and a strong yellow color developed as a result of rapid catalytic degradation within 5 min exposure. Absorbing polymeric substrates served as physical supports of OPH enzyme for sorption reinforced catalytic degradation of MPT. The enzymes were held in molecular layers of buffered polyelectrolytes adsorbed sequentially, constructed through electrostatic interaction without distorting the enzyme architecture. These enzyme friendly substrates could be efficient platforms for protection against biological and chemical threat agents.