Magnetic nanoparticles (MNP) have a great potential application in many fields that include industry, biomedical, environmental, and water treatment for their superparamagnetic properties along with their high surface area, low toxicity, stability to degradation, low cost of fabrication and their versatile surface functionalization with controlled surfaces. Recently, MNP have been reached a new level of interest in surface modification, where these hybrid materials consist of a magnetite core functionalized with different fluorescent molecules. Aforesaid nanoparticles possess two great attractive properties: superparamagnetism and fluorescence. These features give them the possibility to be used not only as nano-adsorbents and nano-carriers but also as optical nano-sensors. Fluorescent magnetic nanocomposites (FMNC) can be synthesized with a variety of fluorescent materials including conjugated polymers, quantum dots, organic dyes, etc. Among those, quantum dots (QD) have been widely studied, but their main problem is that QD contain toxic elements such as cadmium or selenium. Therefore in this work we opted by a new class of organic coating using the biopolymer chitosan (CH), that is well known by their biocompatibility and biodegradability, functionalized with a fluorescent molecule such as carbamoyl benzoic acids (CCA), since CCA are well known for their tunability and high fluorescence properties. Thus, we synthesized a new kind of FMNC by the surface modification of magnetite with CH grafted with CCA by the co-precipitation method. This new magnetic carbamoyl-chitosan (MCCH) was characterized by a broad of techniques such as FT-IR, TGA, TEM, DLS, Z-potential, VSM and BET. Even when MCCH was previously studied by its nano-absorption capacities to improve reclaim water quality, their magnetism, fluorescence and selectivity allowed to determine Hg2+ in a range of 0 to 10 ppm offering a practical recovery enabling their reuse. All these characteristics make them an integral sustainable and eco-friendly system.

New fluorescent magnetic nano-adsorbent as Hg2+ sensor

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.