102: Optimizing green solid-phase peptide synthesis of perylene diimide–peptide π-conjugates

Abstract: Peptide π-electron conjugates are a versatile class of biofunctional materials with unique self-assembly properties, enabling applications in bioelectronics. We report a green solid-phase peptide synthesis (SPPS) strategy for the efficient and safer preparation of peptide–perylene diimide (PDI) conjugates. Target peptides (e.g., GAGA, KKKA, DDDA, DDD) were synthesized using ultrasonication-mediated SPPS with greener solvents such as 2-MeTHF, yielding products of moderate efficiency (30–50%) and high purity. Preliminary solid-phase conjugation to PDI was achieved using safer solvents (DMSO) and a milder base (DBU) at a moderate temperature (60 °C), offering a greener alternative to conventional methods that employ high-temperature (≈130 °C) reactions in NMP with pyridine. By optimizing reaction conditions, including solvent selection and coupling protocols, this approach provides a streamlined and sustainable route to peptide–PDI conjugates, supporting their development for both biological and electronic applications.