Nanocellulose is a hydrophilic polymer with a high zeta potential, surface area, and capability for functionalization, making it an ideal candidate for a filtration material. In this study, the effect of nanocellulose sulfonate group content on adsorption of an opioid simulant was tested. The opioid simulant used was Victoria blue R, an amine dye. Due to the low mechanical strength of the sulfonated nanocellulose, freeze-dried nanocellulose was crosslinked with chitosan. To characterize the nanocellulose FTIR, conductometric titration, and SEM were used. In order to test the viability of the sulfonated nanocellulose as a filter, adsorption isotherms were examined. The adsorption of the dye by the sulfonated nanocellulose followed pseudo-second order kinetics and the Langmuir isotherm. The increase in sulfonate groups led to an increase in the adsorption of Victoria blue R dye. The maximum adsorption of Victoria Blue dye by sulfonated nanocellulose (68.56 mg/g) is significantly higher than those of other adsorbents, like activated carbon (0.59-2.97 mg/g) and magnetic microparticles (40.98 mg/g). Thus, sulfonated cellulose nanocrystals are a promising material for the sequestration of opioids from water.