Mechanical‐Bending‐Induced Fluorescence Enhancement in Plastically Flexible Crystals of a GFP Chromophore Analogue

Abstract

Single crystals of optoelectronic materials that respond to external stimuli, such as mechanical, light, or heat, are immensely attractive for next generation smart materials. Here we report single crystals of a green fluorescent protein (GFP) chromophore analogue with irreversible mechanical bending and associated unusual enhancement of the fluorescence, which is attributed to the strained molecular packing in the perturbed region. Soft crystalline materials with such fluorescence intensity modulations occurring in response to mechanical stimuli under ambient pressure conditions will have potential implications for the design of technologically relevant tunable fluorescent materials.

Pharmaceutical cocrystals: A review of preparations, physicochemical properties and applications

“…Organic crystals are usually brittle and fragile, which largely limit their applications in the fields of pharmaceuticals 135 , biomaterials 136 , optoelectronics 137 , fluorescence 138 and semiconductors 139 . Recently, some studies have reported that a few organic materials could achieve high flexibility by cocrystallization with a suitable coformer 140 , 141 .…”

Quantifiable stretching-induced fluorescence shifts of an elastically bendable and plastically twistable organic crystal

“… 23 Reddy and his colleagues reported single crystals of a green fluorescent protein analogue with irreversible mechanical bending under shear forces and associated unusual enhancement of the fluorescence, which is attributed to the strained molecular packing in the perturbed region. 24 …”

Bending for Better: Flexible Organic Single Crystals with Controllable Curvature and Curvature‐Related Conductivity for Customized Electronic Devices

“…Actually, the mechanical bending will certainly alter the ordered structure of crystals, [1i] possibly further regulating the properties. It is a pity that such a connection has been rarely reflected and realized before [10] . 2) Macroscopic bending (centimeter scale) has been well performed, while sub‐macroscopic bending is worth further exploring [8k] .…”

“…An efficient micro‐space deformation for manipulating crystal packing is more preferred considering the Å‐scale of the lattice size. 3) Present crystal bending always depends on manual operations (by man hands, tweezers, mechanical probes or microcantilevers), [1h, 8d,k,l, 9c, 10] which is experience‐based, time‐consuming and hard to control. A bending without artificial intervention, which means that the crystal grows in bent itself, known as self‐bending, [11] expected to be a key for scale‐up process, has yet to be done in organic crystals, much less to control over the bending curvature.…”