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 mol/L within 10 min. The cellulose matrix and the grafted functional groups (CS, NH) 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 NAg, SAg, and AgS, 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.