Methods and formulations for antimicrobial and anti-biofouling coating comprising: a hollow round colloidal structure, comprising: an active polymer shell; and an active or inert core; wherein the active polymer shell comprises one and more polymers with antimicrobial and anti-biofouling activities selected from the group consisting of polyethylenimine (PEI), functionalized chitosan (CHI), polyquaternium, poly(diallyldimethylammonium chloride) (PDDA) and polyhexamethylene biguanide (PHMD); wherein the active or inert core contains one and more disinfectants, biocides, fragrances or inert solvent; and wherein the hollow round colloidal structure is stable for at least 3 months.