Ultraresponsive Donor–Acceptor System for Transforming Poly(lactic) Acid into Amino Acids with Visible Light

A photocatalytic, green, and cost-effective approach is the most promising pathway for the transformation of sustainable plastic waste, poly­(lactic) acid (PLA). However, PLA degrades into carbon dioxide and water. This degradation process is slow and problematic, as it emits CO2, causing global warming effects. Consequently, there is an urgent need to develop innovative strategies for upcycling PLA into lanthanide as an amino acid for protein formation. Therefore, we report the formation of an ultraresponsive donor–acceptor coupled system, i.e., ferrocene carboxaldehyde (FCaldh) covalently coupled with an amine-modified nanodiamond (ND)-based chromophore (FCaldhCND photocatalyst) for upcycling poly­(lactic acid) into alanine. The FCaldh moiety served as an external light-harvesting component in the conjugated photocatalytic system. The donor–acceptor photocatalytic system (FCaldhCND) led to an amino acid (alanine) generation of 77% in comparison to constituents. This research study presents an attractive approach for upcycling PLA waste and opens avenues for the green synthesis of different types of amino acids.