Amplified spontaneous emission and gain in highly concentrated Rhodamine-doped peptide derivative

Abstract

Bioinspired fluorescence, being widely explored for imaging purposes, faces challenges in delivering bright biocompatible sources. While quite a few techniques have been developed to reach this goal, encapsulation of high-quantum yield fluorescent dyes in natural biological forms suggest achieving superior light-emitting characteristics, approaching amplified spontaneous emission and even lasing. Here we compare gain capabilities of highly concentrated Rhodamine B solutions with a newly synthesized biocompatible peptide derivative hybrid polymer/peptide material, RhoB-PEG1300-F6, which contains the fluorescent covalently bound dye. While concentration quenching effects limit the maximal achievable gain of dissolved Rhodamine B, biocompatible conjugation allows elevating amplification coefficients towards moderately high values. In particular, Rhodamine B, anchored to the peptide derivative material, demonstrates gain of 22–23 cm−1 for a 10−2 M solution, while a pure dye solution possesses 25% smaller values at the same concentration. New biocompatible fluorescent agents pave ways to demonstrate lasing in living organisms and can be further introduced to therapeutic applications, if proper solvents are found.

Differently N‐Capped Analogues of Fmoc‐FF

“…This different rigidity is probably related to the pK a of the two nucleobases. Fluorophores and photoreactive moieties, including anthracene, [74] diazides [75] and diyne units, [76] have been proposed as serviceable chemical entities to improve the mechanical response and the functionality of nanostructured materials [24c,77] . The introduction proposed by Kim et al [78] .…”

Self-Assembling Peptides: From Design to Biomedical Applications

“…Fluorescence bioimaging plays an essential role in biomedical research and treatment, being a widely used technique, for example, in cellular studies to visualize individual functional sites, in applied therapeutics to identify tumors, and to track conformation processes in real time [ 86 ]. The main challenge consists in delivering fluorescent dyes in natural biological forms with greater light-emitting features and amplified and lasting spontaneous emission.…”

“…The main challenge consists in delivering fluorescent dyes in natural biological forms with greater light-emitting features and amplified and lasting spontaneous emission. Machnev et al compared RhoB-PEG1300-F6, a biocompatible peptide derivative material covalently linked to rhodamine B (RhoB), with high concentrated solutions of the same fluorophore and showed that pure RhoB solution demonstrated 25% smaller gain values compared to the dye bound to the peptide derivative material [ 86 ].…”

Bloch-Surface Plasmon Polariton Enhanced Amplified and Directional Spontaneous Emission from Plasmonic Hexagonal Nanohole Array

“…11−13 It becomes progressively important as a competitor or even a substitute of lasing and pulsed source in optical amplifiers. The optical gain media for generating ASE is highly selective, such as optically pumped dye molecules, 14 quantum dots, 15,16 excitons, 17 and electrically pumped quantum wells. 18 Future implementation in optoelectronic devices urges more effective approaches to further enhance the light emission intensity, narrow the emission band, and reduce the threshold of the ASE.…”

“…As a typical light emission phenomenon in optical system, amplified spontaneous emission (ASE) is obviously different from spontaneous emission, which is a characteristic before the laser oscillation threshold and depends strongly on the propagation direction. − It becomes progressively important as a competitor or even a substitute of lasing and pulsed source in optical amplifiers. The optical gain media for generating ASE is highly selective, such as optically pumped dye molecules, quantum dots, , excitons, and electrically pumped quantum wells . Future implementation in optoelectronic devices urges more effective approaches to further enhance the light emission intensity, narrow the emission band, and reduce the threshold of the ASE.…”