Synthesis and characterization of fluorescent gold clusters encapsulated in PNIPAM and PAAM hydrogels for selective detection of mercury in water

MONTI, GUSTAVO ANTONIO; PINO, GUSTAVO A.; ACEVEDO, DIEGO FERNANDO

Environmental Science: Advances

ROYAL SOCIETY OF CHEMISTRY

Año: 2023 vol. 2 p. 1 - 14

2754-7000

The present work describes the synthesis of new nanomaterials based on gold nanoclusters (AuNCs)supported on poly(N-isopropylacrylamide) (PNIPAM) and polyacrylamide (PAAM) hydrogels, as well astheir characterization in terms of structure and physicochemical properties. AuNCs were synthesized byincorporating the metallic precursor (Au3+) into the polymeric matrices and subsequently reducing itwith UV-vis light (l = 365 nm). The materials were characterized by UV-vis, FT-IR, fluorescencespectroscopy, TEM and SEM. Likewise, the thermal properties and the swelling capacity of the differentpolymer matrices were determined. In addition, we present a comparative study with two nanomaterialsregarding their behavior for the selective detection of Hg2+ in water. Furthermore, it is demonstratedthat the polymer matrices influence the nanomaterials´ selectivity to mercury. As the AuNCsfluorescence incorporated in both matrices is quenched by Hg2+, the materials can be used to sensesensitively and selectively Hg2+ in water with a detection limit of 4.1 nM and 1.3 nM for Au-PNIPAM andAu-PAAM NCs, respectively. Summarizing, our study presents a novel, easy and straightforward route tosynthesized nanomaterials with unique optical and chemical properties, which could be used for theconstruction of a portable Hg2+ detection device