New piezoelectric materials based on Phe-Leu and Leu-Phe dipeptides

Short-chain oligopeptides are promising compounds for the development of biocompatible organic piezoelectric materials using the strategy of supramolecular chemistry. The diversity of amino acids available to humankind allows for designing and fine-tuning many piezoelectric materials for various technologies, including biomedicine and green energy. However, to date, the piezoelectric properties of such objects remain practically unstudied. In this paper, we have studied the micro- and nanocrystals of L-phenylalanyl-L-leucine and L-leucyl-L-phenylalanine dipeptides for the first time using piezoresponse force microscopy. The effective piezoelectric coefficients for vertical and lateral displacements were calculated. Methods for forming amorphous films and growing crystals of these dipeptides with the required size are proposed. The results obtained are useful for the design of piezoelectric devices based on dipeptide crystals.