[en] Nowadays, with improvements in technology, smart materials have gained much attention. The objective of the present study is to prepare light-reduction/oxidation responsive alginate nano hydrogels and finishing cotton fabric by these smart hydrogels to produce smart textile. Alginate nano hydrogels were prepared by the reverse emulsification-diffusion method in a water in oil system by using alginate solution as a model polymer and water phase, normal hexane as an oil phase, span 80 as a lipophilic surfactant, Iron (II)-chloride as a cross-linker and light-redox sensitive agent and sodium lactate as a reducing agent. Alginate nano hydrogels were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM) methods and the synthesis of alginate nano hydrogels was confirmed. In the next step, cotton fabrics were finished by these smart hydrogels. Scanning electron microscopy and FTIR test confirmed the presence of alginate nano hydrogels on the fabric. Water retention capacity (WRC) and antibacterial properties were evaluated and the results exhibited the improvement of WRC and antibacterial activity against gram-positive and gram-negative bacteria. These kinds of alginate nano hydrogels made the fabric responsive to light stimuli. In order to evaluate this responsivity, a drug model (folic acid) was loaded in the structure of nano hydrogels by sonification, the rate of release by radiation of ultraviolet light was studied by spectroscopy, and the results proved the light responsivity of these nano hydrogels.