An ionic liquid promoted microwave-hydrothermal route towards highly photoluminescent carbon dots for sensitive and selective detection of iron(iii)†
A facile approach towards photoluminescent carbon dots (CDs) has been developed by the microwave-hydrothermal treatment of rice straw in the mixed solvent of water and ionic liquid (1-allyl-3-methylimidazolium chloride, AMIM-Cl). AMIM-Cl helps to dissolve the cellulose in straw and provides nitrogen atoms for the resulting heteroatom doped CDs. As a result, the straw produced CDs possess a spherical morphology and a high quantum yield of about 22.58%, which is higher than the other CDs prepared from biomass. In addition, the CDs can serve as an effective label-free fluorescent sensor for the detection of Fe(III) ions with a very low detection limit of 200 nM.