A Synthetic Amino Acid Residue Containing A New Oligopeptide-Based Photosensitive Fluorescent Organogel

• Published in: Chemistry, an Asian journal Vol. 8; no. 1; pp. 113 - 120
• Main Authors: Maiti, Dibakar Kumar, Banerjee, Arindam
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2013; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Amino Acids - chemistry; Chemistry; Fluorescence; Gels; isomerization; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Oligopeptides - chemistry; peptides; photochemistry; Rheology; Scanning electron microscopy; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; stilbene; Thermodynamics; X-Ray Diffraction
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.201200617

A synthetic amino acid (with a stilbene residue in the main chain) containing a tripeptide‐based organogelator has been discovered. This peptide‐based synthetic molecule 1 self‐assembles in various organic solvents to form an organogel. The gel has been thoroughly characterized by using various microscopic techniques including field‐emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X‐ray diffraction (XRD), UV‐visible and fluorescence spectroscopy, and rheology. Morphological investigations using FESEM and AFM show a nanofibrillar network structure. Interestingly, the organogel is photoresponsive and a gel–sol transition occurred by irradiating the gel with UV light of 365 nm for 2 h as shown by the UV and fluorescence study. This photoresponsive fluorescent gel holds promise for new peptide‐based soft materials with interesting applications. Light switch: A photoresponsive fluorescent peptide‐based gelator molecule with a stilbene‐containing amino acid residue has been discovered. A trans–cis isomerization of the stilbene portion of the gelator molecule is responsible for the gel–sol transition triggered by UV irradiation (see figure).