Micellar Aggregates Research Articles

Studies on the aggregation behaviour of radiolytically degraded tetra(2-ethyhexyl)diglycolamide in n-dodecane medium during the extraction of trivalent metal ions

The organic phase containing tetra(2-ethylhexy)diglycolamide (TEHDGA) and n-dodecane (n-DD) was irradiated to various absorbed dose levels in a 60Co gamma irradiation chamber. The organic phase subjected to irradiation was classified in to four different categories. The extraction behavior of Nd(III) from nitric acid was studied in the degraded solution of 0.2 M TEHDGA/n-DD and the reverse micellar aggregation behavior of the extracted phase was probed by dynamic light scattering technique and ATR-FTIR spectroscopy. The results revealed that the concentration of TEHDGA decreased upon irradiation and minimized the aggregation in organic phase. The presence of n-DD along with TEHDGA during irradiation enhanced the degradation of TEHDGA, due to sensitization effect. In contrast to the assumption of deteriorating effect of gamma radiation on organic phases, the study showed that the radiolytic degradation of TEHDGA/n-dodecane minimized the aggregation and threw the third phase formation limit of Nd(III) in aqueous phase to higher values.

Sustained release of lipophilic gemcitabine from an injectable polymeric hydrogel for synergistically enhancing tumor chemoradiotherapy

Gemcitabine (Gem), an analogue of deoxycytidine, has potent antitumor activities against various solid tumors and is an excellent radiosensitizer as well. However, Gem has a very short half-life, making it difficult to achieve the long-term synergies between chemotherapy and radiotherapy. Herein, we developed a long-acting Gem delivery system using a palmityl modified Gem derivative (GemC16) as the drug and an injectable and thermosensitive hydrogel as the vehicle, and then combined with multiple radiation therapy for the synergistic treatment of tumors. The thermosensitive hydrogel that exhibited a temperature-responsive sol–gel transition was composed of two poly(D,L-lactic acid-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(D,L-lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymers with different PLGA/PEG ratios. Such a physical hydrogel formed an internal structure of percolated micelle network, in which the polymeric micelles played a reservoir role in effectively solubilizing lipophilic GemC16 in water. In vitro tests manifested that the entrapped GemC16 was, in the form of micelles and micellar aggregates, released out of the hydrogel depot in a sustained pattern for over one month. In vitro cellular assays demonstrated that GemC16 mediated by the polymeric micelles was rapidly internalized to tumor cells via endocytosis. After a single peritumoral administration of the hydrogel system combined with local multiple X ray exposures, the sustained release of GemC16 exerted a long-acting chemotherapy effect and afforded a durable radiosensitization, thereby synergistically enhancing chemoradiotherapy efficacy, inhibiting metastasis and ameliorating complications.

Volumetric Properties of Secondary Butanol and Tertiary Butanol in Water and Aqueous Micellar Systems of Sodium Dodecyl Sulphate

The apparent molal volumes of sec-butanol and t-butanol in water and in aqueous micellar system of sodium dodecyl sulphate have been determined from density measurements at different surfactant concentrations and temperatures. The partial molal volumes of the alcohols in aqueous micellar system at infinite dilution, V20 (mean, mic) were obtained from apparent molal volume data and compared with the corresponding values in aqueous solvent, V20 (mean, aq). The standard partial molal expansibilities, E20 (mean) of the alcohols were evaluated from V20 (mean) data at various temperatures. The transfer apparent molal volumes, ∆φtr0 for the alcohols from water to surfactant-water system are determined from apparent molal volume data. The sign and magnitude of these parameters are used to analyze the location of the solubilizate (alcohols) in the micellar system and the nature of interactions between alcohols and the micellar aggregates.

Flow-Induced Micellar Morphological Transformation in Microfluidic Chips under Nonequilibrium State: From Aggregates to Spherical Micelles

Self-assembly of block copolymers (BCPs) in microfluidic chips is a versatile yet effective route to produce micellar aggregates with various controllable sizes and morphologies. In this study, the morphological transformation of BCP of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) assemblies from irregular aggregates to multicompartment micelles, and ultimately to ordered spherical micelles is demonstrated in microfluidic chips. Our experimental and computational simulation results indicate that transverse diffusion of solvents plays an important role in the morphological transformation of PS-b-P4VP assemblies in the confined flow condition. We find that the mixing time (tmix) between BCP/tetrahydrofuran (THF) solution and water affects the morphological transformation. Micellar morphologies are intended to transform from aggregates to ordered spherical structures under a relatively long mixing time (tmix). In addition, it is observed that the size of the micelles decreases with the increase of flow velocity ratio by tuning the hydrodynamic conditions of the flows. Moreover, by adjusting initial polymer solution concentration, temperature, and the weight fraction of introduced homopolystyrene (hPS), which can affect the viscosity of the BCP solution, the flow diffusion in the microfluidic chip and the resulted micellar structures can be also readily adjusted. The current study provides a new flow-driven method to adjust the micellar ordered structural transformation under nonequilibrium state.

Drug-surfactant comicellization: Propranolol hydrochloride-surface active ionic liquid systems in aqueous medium

Mixed micellization behavior of an antidepressant amphiphilic drug propranolol hydrochloride (PPL) with each of two surface-active ionic liquids (SAILs), 1-decyl-3-methylimidazolium chloride (DMImCl) and 1-hexadecyl-3-methylimidazolium chloride (HDMImCl) in aqueous solutions has been studied using conductometric, and tensiometric techniques. The structures of PPL and SAILs have been optimized using Density Functional Theory (DFT) calculations and the possible coordination of PPL with the head group of the SAILs has also been studied. The critical micellar concentration (cmc) (for pure as well as mixed surfactants), micellar composition of the surfactants, interaction parameter (βR) along with the degree of counterion binding (α) have been ascertained in this study. In particular, the regular solution theory, put forward by Rubingh, was employed to obtain the SAIL-PPL interaction parameters (βR) in the micellar state from the cmc values of the corresponding SAILs and drug in their mixtures. Analyses of the results have also been made on the basis of the theories of Clint and Motomura to gain important insight into the nature of interactions prevailing among the components in the mixed micelle. Different interfacial and thermodynamic parameters for comicellization have also been derived and information as to the spontaneity of the comicellization process, thermal stability of the micellar aggregates, alteration of the surface activity of PPL in presence of the SAILs, geometrical shapes of the micellar aggregates etc. have been obtained.

Quantitative Prediction of the Structure and Viscosity of Aqueous Micellar Solutions of Ionic Surfactants: A Combined Approach Based on Coarse-Grained MARTINI Simulations Followed by Reverse-Mapped All-Atom Molecular Dynamics Simulations.

We address the problem of the quantitative prediction of micelle formation in dilute aqueous solutions of ionic surfactants using sodium dodecyl sulfate (SDS) as a model system through a computational approach that involves three steps: (a) execution of coarse-grained simulations based on the MARTINI force field (with slightly modified parameters to afford the formation of large micelles); (b) reverse mapping of the final self-assembled coarse-grained configuration into an all-atom configuration; and (c) final relaxation of this all-atom configuration through short-time (on the order of a few tens of nanoseconds), detailed isothermal-isobaric molecular dynamics simulations using the CHARMM36 force field. For a given concentration of the solution in SDS molecules, the modified MARTINI-based coarse-grained simulations lead to the formation of large micelles characterized by mean aggregation numbers above the experimentally observed ones. However, by reintroducing the detailed chemical structure through a strategy that solves a well-defined geometric problem and re-equilibrating, these large micellar aggregates quickly dissolve to smaller ones and equilibrate to sizes that perfectly match the average micelle size measured experimentally at the given surfactant concentration. From the all-atom molecular dynamics simulations, we also deduce the surfactant diffusivity DSDS and the zero-shear rate viscosity, η0, of the solution, which are observed to compare very favorably with the few experimental values that we were able to find in the literature.

Octenyl-succinylated inulin for the encapsulation and release of hydrophobic compounds

Octenyl-succinylated inulins (OSA-inulin) were synthesized in aqueous solutions using inulin with varying degrees of polymerization (DP). They were characterized using 1H NMR and FTIR and their degrees of substitution were determined. All the samples formed micellar aggregates in aqueous solution above a critical aggregation concentration (CAC) and solubilized beta-carotene. The amount of beta carotene solubilized within the micelles ranged from 12 to 25 mg/g of OSA-inulin and depended on the inulin molar mass. Dynamic light scattering showed that the aggregates, with and without dissolved beta-carotene, were ∼10–15 nm in size and this was confirmed by Transmission Electron Microscopy which also indicated that the micelles had a globular shape. OSA-inulin particles containing encapsulated beta-carotene were produced by freeze-drying. The encapsulated beta-carotene was not released from the freeze-dried particles when introduced into simulated gastric fluid at pH 2.5 but was readily released in simulated small intestinal fluid at pH 7. The results demonstrate the potential application of OSA-inulin in the encapsulation, dissolution and targeted delivery of hydrophobic drug molecules for nutraceutical, pharmaceutical and medical applications.

Characterisation of four hotdog-fold thioesterases for their implementation in a novel organic acid production system

With increasing interest in the diverse properties of organic acids and their application in synthetic pathways, developing biological tools for producing known and novel organic acids would be very valuable. In such a system, organic acids may be activated as coenzyme A (CoA) esters, then modified by CoA-dependent enzymes, followed by CoA liberation by a broad-acting thioesterase. This study has focused on the identification of suitable thioesterases (TE) for utilisation in such a pathway. Four recombinant hotdog-fold TEs were screened with a range of CoA esters in order to identify a highly active, broad spectrum TE. The TesB-like TE, RpaL, from Rhodopseudomonas palustris was found to be able to use aromatic, alicyclic and both long and short aliphatic CoA esters. Size exclusion chromatography, revealed RpaL to be a monomer of fused hotdog domains, in contrast to the complex quaternary structures found with similar TesB-like TEs. Nonetheless, sequence alignments showed a conserved catalytic triad despite the variation in quaternary arrangement. Kinetic analysis revealed a preference towards short-branched chain CoA esters with the highest specificity towards DL-β-hydroxybutyryl CoA (1.6 × 104 M−1 s−1), which was found to decrease as the acyl chain became longer and more functionalised. Substrate inhibition was observed with the fatty acyl n-heptadecanoyl CoA at concentrations exceeding 0.3 mM; however, this was attributed to its micellar aggregation properties. As a result of the broad activity observed with RpaL, it is a strong candidate for implementation in CoA ester pathways to generate modified or novel organic acids.

Aggregation of Lipid A Variants: A Hybrid Particle-Field Model

Lipid A is one of the three components of bacterial lipopolysaccharides constituting the outer membrane of Gram-negative bacteria, and is recognized to have an important biological role in the inflammatory response of mammalians. Its biological activity is modulated by the number of acyl-chains that are present in the lipid and by the dielectric medium, i.e., the type of counter-ions, through electrostatic interactions. In this paper, we report on a coarse-grained model of chemical variants of Lipid A based on the hybrid particle-field/molecular dynamics approach (hPF-MD). In particular, we investigate the stability of Lipid A bilayers for two different hexa- and tetra-acylated structures. Comparing particle density profiles along bilayer cross-sections, we find good agreement between the hPF-MD model and reference all-atom simulation for both chemical variants of Lipid A. hPF-MD models of constituted bilayers composed by hexa-acylated Lipid A in water are stable within the simulation time. We further validate our model by verifying that the phase behavior of Lipid A/counterion/water mixtures is correctly reproduced. In particular, hPF-MD simulations predict the correct self-assembly of different lamellar and micellar phases from an initially random distribution of Lipid A molecules with counterions in water. Finally, it is possible to observe the spontaneous formation and stability of Lipid A vesicles by fusion of micellar aggregates.

Physicochemical Evaluation of Insulin Complexes with QPDMAEMA-b-PLMA-b-POEGMA Cationic Amphiphlic Triblock Terpolymer Micelles.

Herein, poly[quaternized 2-(dimethylamino)ethyl methacrylate-b-lauryl methacrylate-b-(oligo ethylene glycol)methacrylate] (QPDMAEMA-b-PLMA-b-POEGMA) cationic amphiphilic triblock terpolymers were used as vehicles for the complexation/encapsulation of insulin (INS). The terpolymers self-assemble in spherical micelles with PLMA cores and mixed QPDMAEMA/POEGMA coronas in aqueous solutions. The cationic micelles were complexed via electrostatic interactions with INS, which contains anionic charges at pH 7. The solutions were colloidally stable in all INS ratios used. Light-scattering techniques were used for investigation of the complexation ability and the size and surface charge of the terpolymer/INS complexes. The results showed that the size of the complexes increases as INS ratio increases, while at the same time the surface charge remains positive, indicating the formation of clusters of micelles/INS complexes in the solution. Fluorescence spectroscopy measurements revealed that the conformation of the protein is not affected after the complexation with the terpolymer micellar aggregates. It was observed that as the solution ionic strength increases, the size of the QPDMAEMA-b-PLMA-b-POEGMA/INS complexes initially decreases and then remains practically constant at higher ionic strength, indicating further aggregation of the complexes. atomic force microscopy (AFM) measurements showed the existence of both clusters and isolated nanoparticulate terpolymer/protein complexes.

Tethering (Arene)Ru(II) Acylpyrazolones Decorated with Long Aliphatic Chains to Polystyrene Surfaces Provides Potent Antibacterial Plastics.

The acylpyrazolone proligands HQR (HQR in general, in detail: HQCy = 1-phenyl-3-methyl-4-carbonylcyclohexyl-5-pyrazolone, 4-C(O)-phenyl, HQPh = 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, HQC17 = 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone, HQC17,Ph = 1-phenyl-3-stearyl-4-benzoyl-5-pyrazolone) were synthesized and reacted with (arene)Ru(II) acceptors affording complexes [(arene)Ru(QR)Cl] (arene = cymene (cym) or hexamethylbenzene (hmb)). The complexes were characterized by elemental analyses, thermogravimetric analysis-Differntial Thermal Analysis (TGA-DTA), IR spectroscopy, ESI-MS and 1H, and 13C NMR spectroscopy. Complexes [(arene)Ru(QR)Cl] where QR = QC17 and QC17,Ph, due to the long aliphatic chain in the ligand, afford nanometric dispersions in methanol via self-assembly into micellar aggregates of dimensions 50–200 nm. The antibacterial activity of the complexes was established against Escherichia coli and Staphylococcus aureus, those containing the ligands with a long aliphatic chain being the most effective. The complexes were immobilized on polystyrene by a simple procedure, and the resulting composite materials showed to be very effective against E. coli and S. aureus.

A Classical Molecular Dynamics Simulation Study of Interfacial and Bulk Solution Aggregation Properties of Dirhamnolipids.

The rhamnolipids are a unique class of biosurfactants produced by the bacteria Pseudomonas aeruginosa. These molecules display a high level of surface activity as well as biodegradability. In this study nonionic dirhamnolipid was investigated by utilizing molecular dynamics simulation at the air-water interface as well as in bulk water. Detailed structural analysis is presented for both the interfacial simulations and the simulations in solution. A systematic comparison was made between our previous work on the monorhamnolipid at the air-water interface and in bulk water. The presence of a second rhamnose group in dirhamnolipid did not show any significant change in the aggregation at the air-water interface. An increase in the molecular weight resulted in the larger surface area per monomer for dirhamnolipid compared to monorhamnolipid at the air-water interface. However, aggregation of dirhamnolipid in bulk water was affected by the presence of a second rhamnose group. Dirhamnolipid aggregates into micellar structure around ∼N22 which was lower than the monorhamnolipid aggregation number ∼N40. The hydrophobic component of the dirhamnolipid was enhanced to balance the higher hydrophilic component. An increase in alkyl chain length has shown that the enhanced hydrophobic component supports the formation of micellar aggregates up to ∼N30 and above, which was not observed in dirhamnolipid with a shorter alkyl chain length.

Preparation and characterization of a supramolecular hydrogel made of phospholipids and oleic acid with a high water content.

A hydrogel formed with phospholipids and fatty acids would be of great interest in the medical field due to the biological relevance that these molecules have in living organisms. However, the tendency of phospholipid mixtures to form vesicular or micellar aggregates at high water content hinders the formation of this type of hydrogel. In this study, a highly hydrated hydrogel (95% water) was formed with hydrogenated phosphatidylcholine and oleic acid. The preparation method involved a freeze-heating cycle of the aqueous lipid mixture, favouring the supramolecular aggregation of these molecules into a microscopic spongy morphology. Confocal fluorescence imaging showed that the microstructure of the hydrogel is made from the aggregation of giant multilamellar vesicles (5-20 μm diameter) while transmission electron microscopy revealed the existence of nanosized unilamellar vesicles (150 nm diameter) coexisting with lipid lamellae. Despite this type of aggregation, X-ray scattering experiments performed on the hydrogel show almost no correlation between lipid membranes. In terms of rheological properties, the material shows a prevalent elastic behaviour and low structural strength, a consequence of non-covalent interactions. With such properties and composition, this structured but easily deformable material might become a useful tool for biomedical applications.

Polymers prepared through an "ATRP polymerization-esterification" strategy for dual temperature- and reduction-induced paclitaxel delivery.

Clinically, the nanotherapy of tumors has been limited by the drug content, efficiency of targeted release, and bioavailability. In this study, we fabricated an amphiphilic block polymer, poly(2-methacryloyloxyethyl thiocticcarboxylate)-block-poly(N-isopropylacrylamide) (PMAOETC-b-PNIPAM), using an “ATRP polymerization–esterification” strategy for paclitaxel (PTX) delivery. The hydrophobic drug paclitaxel was encapsulated based on hydrogen bond interactions between PTX and the PMAOETC and PNIPAM blocks, together with hydrophobic interactions between PTX and PMAOETC segments, affording PTX-laden polymer micelles with ∼30% drug loading content. The critical micelle concentration of the PTX-loaded polymeric micellar aggregates was 34.53 mg l−1, as determined through fluorescence spectroscopy, which indicated favorable stability during infinite dilution by body fluids. The phase transition temperature of the micelles was tunable (36.10–39.48 °C) via adjusting the lengths of the blocks. The PTX-laden micelles showed the release of a significant amount of PTX in cancerous tissue, while negligible cytotoxicity was shown against HCT-116 cells in PBS at pH 7.4 and 37 °C. Further in vivo anticancer studies revealed that antitumor treatment using the PTX-laden micelles caused a significant suppression in tumor volume compared with a free-PTX-treated group. This study provides a reference for improving drug content levels and optimizing the therapeutic effects of drug delivery systems from the perspective of polymer preparation.

Controlling the properties of the micellar and gel phase by varying the counterion in functionalised-dipeptide systems.

The micellar aggregates formed at high pH for dipeptide-based gelators can be varied by using different alkali metal salts to prepare the solutions. The nature of the micellar aggregates directly affects the properties of the resulting gels.

Changes in Phase Behavior from the Substitution of Ethylene Oxide with Carbon Dioxide in the Head Group of Nonionic Surfactants.

Nonionic ethylene oxide (EO)‐based surfactants are widely employed in commercial applications and normally form gel‐like liquid crystalline phases at higher concentrations, rendering their handling under such conditions difficult. By incorporating CO2 units in their hydrophilic head groups, the consumption of the petrochemical EO was reduced, and the tendency to form liquid crystals was suppressed completely. This surprising behavior was characterized by rheology and studied with respect to its structural origin by means of small‐angle neutron scattering (SANS). These experiments showed a strongly reduced repulsive interaction between the micellar aggregates, attributed to a reduced hydration and enhanced interpenetration of the head groups owing to the presence of the CO2 units. In addition, with increasing CO2 content the surfactants became more efficient and effective with respect to their surface activity. These findings are important because the renewable resource CO2 is used, and the CO2‐containing surfactants allow handling at very high concentrations, an aspect of enormous practical importance.

Physicochemical and spectral evaluation of the interactional behavior of nicotinic acid (vitamin B3) with mixed [sodium deoxycholate (bile salt) + cetyltrimethylammonium bromide] surfactants

Aggregation behavior of anionic bio-surfactant; sodium deoxycholate (SDC) and cationic surfactant; cetyltrimethylammonium bromide (CTAB) and their mixtures at different mole fractions, αSDC = (0.90026, 0.88416, and 0.69438) has been examined in water as well as in aqueous solutions of nicotinic acid at (298.15, 308.15, and 318.15) K by employing various techniques such as conductivity, density, sound velocity, UV–visible spectroscopy, and dynamic light scattering (DLS) studies. From the critical micelle concentration (CMC) and the degree of ionization (α) of micelle, thermodynamic parameters {standard Gibbs free energy (), enthalpy (), and entropy () of micellization} have been evaluated and analyzed for surfactants studied in water and in (1, 2, and 3) × 10−4 mol kg−1 nicotinic acid(aq) solutions at (298.15, 308.15, and 318.15) K. The CMC values for both the pure and mixed (SDC + CTAB) surfactants were found to increase with increase in concentration of nicotinic acid. The partial specific volume (φv), isentropic compressibility (κs), and partial specific isentropic compressibility (φκ) were estimated from density and speed of sound data. UV–vis absorption spectra of 1 × 10−4 mol kg−1 nicotinic acid(aq) solutions were also recorded in presence of surfactants studied at αSDC = (0.90026, 0.88416, 0.69438) and T = 298.15 K. Hydrodynamic diameters (Dh) of micellar aggregates for both pure and mixed surfactants were analyzed through the DLS studies performed at 298.15 K. The results from all the studies suggest the supremacy of both hydrophobic and electrostatic interactions between the nicotinic acid and the mixed micellar aggregates.

Synthesis and Self-Assembly of Multistimulus-Responsive Azobenzene-Containing Diblock Copolymer through RAFT Polymerization.

This paper gathered studies on multistimulus-responsive sensing and self-assembly behavior of a novel amphiphilic diblock copolymer through a two-step reverse addition-fragmentation transfer (RAFT) polymerization technique. N-Isopropylacrylamide (NIPAM) macromolecular chain transfer agent and diblock copolymer (poly(NIPAM-b-Azo)) were discovered to have moderate thermal decomposition temperatures of 351.8 and 370.8 °C, respectively, indicating that their thermal stability was enhanced because of the azobenzene segments incorporated into the block copolymer. The diblock copolymer was determined to exhibit a lower critical solution temperature of 34.4 °C. Poly(NIPAM-b-Azo) demonstrated a higher photoisomerization rate constant (kt = 0.1295 s−1) than the Azo monomer did (kt = 0.088 s−1). When ultraviolet (UV) irradiation was applied, the intensity of fluorescence gradually increased, suggesting that UV irradiation enhanced the fluorescence of self-assembled cis-isomers of azobenzene. Morphological aggregates before and after UV irradiation are shown in scanning electron microscopy (SEM) and dynamic light scattering (DLS) analyses of the diblock copolymer. We employed photoluminescence titrations to reveal that the diblock copolymer was highly sensitive toward Ru3+ and Ba2+, as was indicated by the crown ether acting as a recognition moiety between azobenzene units. Micellar aggregates were formed in the polymer aqueous solution through dissolution; their mean diameters were approximately 205.8 and 364.6 nm at temperatures of 25.0 and 40.0 °C, respectively. Our findings contribute to research on photoresponsive and chemosensory polymer material developments.

Probe Molecules for Pulsed‐Field‐Gradient Diffusion Nuclear Magnetic Resonance Experiments on Micelles

AbstractNuclear magnetic resonance (NMR) diffusion measurements of surfactants suffer from fast exchange of the surfactant between the micellar aggregate and bulk solution. Therefore, hydrophobic probe molecules are commonly used to directly measure aggregate diffusion under the assumption that the probe molecules remain solubilized inside the micelles. Aggregate size is then determined or estimated from the aggregate diffusion value. Unfortunately, the probe molecule also experiences rapid exchange between the aggregate and bulk, leading to inaccurate or unreasonable micelle diffusion values, a fact that has often been ignored in the literature. In this article, we present a systematic evaluation of probe molecules in cationic and anionic surfactants, obtained by measuring the diffusion of probe molecules with varying hydrophobicity. We find that an octanol–water partition coefficient of at least ~5 is required for correct measurements of aggregate diffusion in the systems studied. Notably, some commonly used probes have a partition coefficient much lower than five and are therefore not suitable for aggregate diffusion measurements. Consideration of these results will help researchers obtain accurate results for micelle sizing or partitioning studies with pulsed‐field‐gradient NMR.

Fluorescent signal transduction in a self-assembled Hg2+ chemosensor tuned by various interactions in micellar aqueous environment

A new OFF-ON fluorescent chemosensor for ions Hg2+ in water has been designed by associating fluorophore 10-methylacridinium perchlorate (MA+ClO4−) with a selective lipophilic sulfur-containing ligand, such as N,N-bis (2-hydroxyethylthio-1-ethyl)dodecyl amine (DBSO). The communication between the two subunits is only due to their spatial closeness, ensured by sodium dodecyl sulfate (SDS) micellar aggregates. The quenching of MA+ fluorescence is ascribed to a photoinduced electron-transfer from the ligand to the excited fluorophore, still the emission is quickly restored by addition of Hg2+ (as chloride salt) due to the complex formation between ligand and metal. The sensitivity of the system improves by decreasing the ligand concentration, as well as by changing the stoichiometry of the ligand-Hg2+ complex from 1:1 to 2:1. DFT calculations give interesting insights into the structures of the complexes and provide useful information on the sensorial activity experimentally observed. The replacement of MA+ClO4− with 9-cyanoanthracene, a fluorophore differently localized on the micellar aggregate, highlights the effect of Cl− coordination to the complexed Hg2+ on the operating mechanism of the sensor. These results demonstrate as the micellar aggregates provide for a straightforward means to regulate the response of the sensorial system without altering the recognition or reporter unit.