Subhasish Roy, Birla Institute of Technology and Science–Pilani, Sancoale, Goa, India, and colleagues addressed two major challenges: removing toxic p-nitrophenol (p-NP) from water and converting it into p-aminophenol (p-AP), a valuable chemical used in drug synthesis. They also addressed the need for sustainable materials that can simultaneously act as antibacterial agents and environmental catalysts.
The team developed hybrid hydrogels from fluorenylmethyloxycarbonyl-tyrosine (Fmoc-Y) and fluorenylmethyloxycarbonyl-tryptophan (Fmoc-W), dissolved in phosphate buffer and phosphate-buffered saline. Self-assembly was induced through a sequence heating, cooling, and shaking. Incorporating gold and silver ions (HAuCl₄ and AgNO₃) generated nanoparticles in situ over seven days without the use of toxic reducing agents. UV–Vis spectroscopy, fluorescence, FTIR, X-ray diffraction, FE-SEM, and HR-TEM confirmed the formation of crystalline nanoparticles embedded within nanofibrillar networks.
These hybrid materials efficiently catalyzed the reduction of p-NP to p-AP in aqueous media. Xerogels showed enhanced reaction rates due to higher surface area and agitation during stirring. Fmoc-Y–AuNP xerogels achieved the best catalytic performance, with a turnover frequency (TOF_max) of 133.08 h⁻¹. Both hydrogels and xerogels retained structure and activity over multiple reuse cycles. They also showed strong antibacterial activity and superior catalytic efficiency compared with previous amino acid-based systems, offering a sustainable approach to environmental remediation.
Overall, these dual-function materials remove toxins and eliminate bacteria from water. Their simplicity, sustainability, and high performance make them promising for water purification, environmental cleanup, and green chemical production. Future work could explore scaling up, integrating into filtration systems, or adapting the platform for other pollutants and reactions.
- Fmoc-Appended redox active aromatic amino acids capped nanoparticles embodied sustainable antibacterial catalytic hydrogels for the production of value-added chemical
Swaraj Ganesh Gaonkar, Ritu Raj Patel, Meenakshi Singh, Biplab Mondal, Sunil Kumar Meena, Subhasish Roy
Adv. Sustain. Syst. 2025
https://doi.org/10.1002/adsu.202500930
