Synthesis of dextran-graft-poly(hydroxyethyl methacrylate) gels as a new fluoride biosorbent was considered in this work. For this propose, the Taguchi experimental design method was used for optimizing the synthetic conditions of the gels to reach high level of fluoride absorbency. The effects of three main parameters including concentrations of monomer (hydroxyethyl methacrylate), crosslinking agent (ethylene glycol dimethacrylate), and initiator (ammonium persulfate) on the final properties of the prepared gels were investigated. The proposed mechanism for grafting and chemically crosslinking reactions was proved with equilibrium water absorption, Fourier-transformed infrared, scanning electron microscopy, and thermogravimetric analysis. Under the optimized synthetic conditions, the maximum fluoride adsorption capacity in distilled water was found to be 8312 (mg fluoride/kg dried gel). As well, the loading of prepared gels with silver nanoparticles has been considered to achieve antibacterial activity. The silver nanoparticles loaded gels showed strong antibacterial activity against Gram-negative Escherichia coli bacterium. Therefore, these new gels can be considered as a potential candidate to develop an efficient antibacterial fluoride biosorbent for water treatment applications.