Phenylalanine-based low-molecular-weight gelator for the removal of metal ions and dyes from wastewater

Increasing water pollution is a major concern for the global community. So, purification and reuse of wastewater are very much urgent. In this work, methyl ester of phenylalanine (Phe-OMe), a non-gelator, has been successfully applied to produce two-component charge transfer–induced organogel and metallohydrogel using picryl chloride and Cu(II) respectively. These gels and their gelation processes were utilized to mop up different toxic metal ions and ionic dyes (especially zwitterionic dye) from wastewater. Phe-OMe can drop down these metal concentrations below the permissible limit of WHO within 10 min. Interestingly, the organogel instantly turns into sol upon the addition of either base or acid. This property makes the gel act as sensors of harmful acidic and basic vapors like HCl, ammonia, and so on in the laboratories and in different industries.