A Glimpse of Our Journey into the Design of Optical Probes in Self‐assembled Surfactant Aggregates

Abstract

Dynamic self-assembling amphiphilic surfactant molecules, popularly known as "micelles", have received widespread attention, due to their ability to modulate the photophysical properties of various organic dyes upon encapsulation. Along with their well-known use as cleaning agents, catalysts in organic reactions, and even for drug delivery purposes, these surfactant assemblies also show promising pertinence in the recognition of both ionic and nonionic targeted analytes. Low micropolarity and relatively hydrophobic environments promote their interaction with ionic analytes, whereas neutral species mostly affect the aggregation pattern of the probe molecules upon partitioning inside the micellar hydrophobic milieu. The environment-sensitive nature of micelle-based self-assembled probes also prompts us to devise new sensor arrays for the recognition of multiple analytes. While this account will largely focus on our own work in developing surfactant-triggered self-assembled sensors, our findings have been placed in the context of the relevant contributions from others during their strategic evolution.

Tunable Emission from Fluorescent Organic Nanoparticles in Water: Insight into the Nature of Self‐Assembly and Photoswitching

“…However,t he trailing region of the absorption spectrum (360-430 nm) exclusivelyo riginated from the Pybpa molecules in the aggregated state (nanoparticle excitation range) and could be observed only in water. [14] As expected, excitation at 340 nm, where the Pybpa monomer-like excitation spectrum showedamaximum, resulted in an emission profile with prominentP ybpa-monomer-like emission band ( % 397 nm band). Similarly,since the excitation spectra for Pybpa nanoparticle emission showed ap eak around 370 nm, excitation of Pybpa nanoparticles in water at 370 nm led to the nanoparticle emissionb and ( % 500 nm band) being dominant.…”

Nanostructured Luminescent Micelles: Efficient “Functional Materials” for Sensing Nitroaromatic and Nitramine Explosives

“…In the last decades, significant advancement has been made to construct the luminescent micellar systems for sensing target analytes, ion transport, and bioimaging. These luminophoric materials are used to demonstrate the rudimentary models for various CT/ET processes in an aqueous solution in the presence of various chemical entities [1][2][3][4][5][6][7]. Based on the fundamental idea of CT/ET transition, a considerable number of elegant luminous micellar systems are developed for sensing metal ions [8][9][10][11][12] and anions [13][14][15], biomolecules [16][17][18][19][20], detection of explosive [21][22][23][24][25], etc.…”

Motion‐Induced Changes in Emission as an Effective Strategy for the Ratiometric Probing of Human Serum Albumin and Trypsin in Biological Fluids

“…This result might be ex-pected, because, in the l = 400 nm band, the emission response is mostly dominated by nonspecific electrostatic interactions.S urfactants can destroy the native structure of the albumin protein and preferentially bind to its hydrophobic pockets, which become exposed during denaturation. [47,48] Thus, when the emissionr esponse of compound 1 towards HSA was monitored in the presence of cetyltrimethylammonium bromide (CTAB), no red-shifted emission band was observed (see the Supporting Information, Figure S10). This resulta lso indicated that the red-shifted emission band at l = 454 nm was owing to the encapsulation of dye molecules inside hydrophobic pockets of the protein.…”