Stepwise Assembly Protocols for the Rational Design of Lanthanide Functionalized Carbon Dots-Hydrogel and its Sensing Evaluation

Inorganic-organic optical probe based on lanthanide emission will provide a new way for specific applications. In this work, sarcosine and urea are selected as raw materials to synthesize carbon dots with cyan-emissive color. In the next step, indicator components (Ethylene Diamine Tetraacetic Acid and lanthanide ions) are incorporated onto carbon quantum dots (CQDs) and the flexible alginate hydrogel is employed as the host to accommodate the emissive species. The soft material can exhibit typical red and green emissions. Its luminescence is responsive to calcium ions and the detection limit has been calculated to be 0.84 μM and 0.92 μM respectively. Such optical device can be employed as a portable probe in a variety of scientific fields due to its convenience and flexibility.