Fluorescence in “Nonfluorescent” Polymers

Abstract

Recently, a great deal of research has been started on generating fairly strong photoluminescence from organic molecules without having any conjugated π-system or fluorophore. Discrete chromophores or auxochromophores termed as “subfluorophores” may undergo “space conjugation” via co-operative intramolecular conformation followed by intermolecular aggregation to generate fluorescence or sometimes phosphorescence emission. Polymeric materials are important in this regard as nonconjugated polymers self-assemble/aggregate in a moderately concentrated solution and also in the solid state, producing membranes, films, and so forth with good physical and mechanical properties. Therefore, promoting fluorescence in these commodity polymers is very much useful for sensing, organic light emitting diodes (OLED), and biological applications. In this perspective, we have discussed the aggregation-induced emission from four different types of architectures, for example, (i) dendrimers or hyperbranched polymers, (ii) entrapped polymeric micellar self-assembly, (iii) cluster formation, and (iv) stretching-induced aggregation, begining with the genesis of fluorescence from aggregation of propeller-shaped small organic molecules. The mechanism of induced fluorescence of polymers with subfluorophoric groups is also discussed from the theoretical calculations of the energy bands in the aggregated state. Also, an attempt has been made to highlight some useful applications in the sensing of surfactants, bacteria, cell imaging, drug delivery, gene delivery, OLED, and so forth.

Structural Characterization of a New Collagen Biomimetic Octapeptide with Nanoscale Self‐Assembly Potential: Experimental and Theoretical Approaches

“…[46] However, according with a recent work the emission of light in visible range could be attributed to a more complex phenomenon. [47] In addition, the excitation spectrum of FRS peptide (spectrum 4, Figure S4), recorded at an emission of 400 nm, is also support-Table 1. The gradient profile used to separate FRS octapeptide by reversephase chromatography using C 18 -Reveleris and C 18 -Vydac columns.…”

Non-Conventional Fluorescence and Cytotoxicity of Two Aliphatic Hyperbranched Polymer Dots Having Poly(amic acid) Structures: Implications for Labeling Nanodrug Carriers

“…Non-conventional PDs that display stable fluorescence without photobleaching have been suitable for use as long-term fluorescent nanocarriers. 34…”

Fluorescent Polymers Conspectus

“…Because of this high demand, there has been a lot of interest in fluorescent polymers (FPs)research ( Figure 2 ), due to their fascinating properties such as their increased signal response even after disturbance due to cooperative conformational effects of its chain segments. This is especially advantageous due to its superior visco-elastic and mechanical properties, which aid in the manufacturing of new devices [ 14 , 15 , 16 , 17 , 18 , 19 ]. FPs, similar to small fluorescent molecules, have a wide range of uses for sensing [ 20 , 21 ] and imaging [ 22 , 23 , 24 , 25 , 26 , 27 ], optoelectronics [ 28 ], fluorescent bioprobes [ 29 ], molecular imaging [ 30 ], photodynamic treatments [ 31 ], OLEDs [ 32 ], storage data security [ 33 ], encryption [ 34 ], anti-counterfeiting materials [ 35 ], and other fields [ 27 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ].…”