Peptide-tethered Perylenebisimide Aggregates with Copper Nanoclusters showing Thermoresponsive and Photoresponsive Properties

A centrally located dipeptide(P) covalently attached to two perylene bisimide units [(PBI)(2)P] was synthesized and it was used to fabricate a hybrid system by aggregating with blue-emitting, atomically precise copper nano-clusters (Cu NCs). The interactions between these components [(PBI)(2)P] and Cu NCs] was thoroughly investigated by UV-Vis spectroscopy and field emission gun transmission electron microscopy (FEG-TEM).The effect of interaction between components on the optical properties of the hybrids was investigated by fluorescence spectroscopy. Interestingly, this hybrid system shows fluorescence thermometric behaviour at the 20-50 & DEG;C temperature range with a promising reversible switchable fluorescence property. Photo-switching property is enhanced significantly in the hybrid compared to that of the peptide tethered pelylene bisimides as it is evident from the improvement of photocurrent gain (I-on/I-off) from 2.6 in [(PBI)(2)P] to 6.9 in the hybrid. Modulation of photo-switching property along with the thermo-sensitive fluorescence property in this hybrid holds a future promise for fabrication of devices from the peptide based hybrids.