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 ( C S, NH 2 ) 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 Ag 2 S, 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 + .