Cellulose-based colorimetric sensor with N, S sites for Ag+ detection

A novel cellulose-based colorimetric sensor (DAC-Tu) with N, S sites for Ag+ was prepared. The DAC-Tu exhibited excellent selectivity and sensitivity for Ag+ with a naked eyes color change from white to black in mixed metal ions aqueous solutions. The naked-eye in-situ detection limit of DAC-Tu for Ag+ was 10(-6) mol/L within 10 min. The cellulose matrix and the grafted functional groups (-Cd=S, -NH2) of DAC-Tu all contributed to the low naked-eye in-situ detection limit. The mechanism of the visual recognition of DAC-Tu sensor for Ag+ was proposed, the N and S atoms of DAC-Tu preferentially coordination chelated with Ag+ to form N-Ag, S-Ag, and Ag2S, and enriched on the cellulose matrix, thus the DAC-Tu presented different color change in response to different concentrations of Ag+. The as-prepared DAC-Tu colorimetric sensor showed a great application prospect for in-situ naked eyes detection of Ag+. (C) 2020 Published by Elsevier B.V.