Formation Of Langmuir Monolayers Research Articles

Thin-film polydiacetylenes of a stable blue phase based on symmetrical and unsymmetrical diacetylene <i>N</i>-arylcarbamates

The conditions and features of the formation of Langmuir monolayers of symmetrical and asymmetrical diacetylene N-arylcarbamates and the structural organization of Langmuir-Schaefer films based on them were studied. Photopolymerization of monolayer solid films of two types of molecules was monitored using absorption spectroscopy and showed the transition of diyne molecules to the blue phase polydiacetylene state. The efficiency of the solid-phase topochemical polymerization reaction in a film of symmetrical diynes turned out to be 5 times higher than in a film of asymmetrical diyne molecules. The morphology of monolayer surfaces before and after UV irradiation was studied using scanning electron microscopy.

Reversible in Situ Control over Monolayer Organization.

Cr2+ and Cr3+ ions are shown to mediate the formation, morphology, and organization of arachidic acid (AA) Langmuir-Blodgett (LB) monolayers. This finding, based on cyclic voltammetry (CV), linear sweep voltammetry (LSV) and fluorescence recovery after photobleaching (FRAP) measurements, show that Langmuir monolayer formation depends on subphase pH and metal ion concentration. Following monolayer deposition on ITO, the LB monolayer organization can be modified reversibly through control of the Cr oxidation state, which has not been shown before by other monolayers formed with other divalent metal ions. The dynamics and the mobility of a chromophore (perylene) incorporated into the monolayer sense changes in Cr oxidation state-dependent organization of the LB monolayer. Demonstrating reversible changes in monolayer organization provides an opportunity to control chemical and electron access to the interface support.

Формирование монослоев Ленгмюра из нативных фосфолипидов бактерий различных систематических групп

Phospholipids are the most important structural elements of the bacterial cell wall, participate in the adaptation of microorganisms to the environment and can act as biomarkers for environmental changes and one of the components of environmental monitoring. Native phospholipids are used to form models of cell membranes, the biophysical properties of which can be studied by the Langmuir-Blodgett method. The aim of this work was to isolate and characterize the phospholipids of the cell membranes of the bacteria Staphylococcus aureus and Bacillus cereus and the formation of Langmuir monolayers based on them. The composition and ratio of fatty acids were determined by gas-liquid chromatography of fatty acid methyl esters. Fatty acids, found in the extract of the bacteria S. aureus 209-P and B. cereus 8035, are: hexadecanoic, trans-9-octadecenoic, octadecanoic, tetradecanoic, 13-methyltetradecanoic, 14-methylpentadecanoic, 15-methylhexadecanoic, cis-9-octadecanoic. To form a monolayer, a working solution of native phospholipids in chloroform with a concentration of C = 10-3 М was used. The monolayer formed when a 50 μl solution of a phospholipid mixture is applied to the surface has a more perfect structure, which is manifested in the constancy of its mechanical properties. The analysis of the obtained data has not yet revealed a clear dependence of the monolayer parameters on temperature. The changes in the compression modulus and compressibility were very minor. With an increase in the salt concentration, both an increase and a decrease in the compression modulus, and, consequently, the rigidity of the monolayer, is observed.

Interaction of sakuranetin with unsaturated lipids forming Langmuir monolayers at the air-water interface: A biomembrane model

This study investigates the interaction between sakuranetin, a versatile pharmaceutical flavonoid, and monolayers composed of unsaturated phospholipids, serving as a surrogate for cell membranes. The phospholipids were 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE). We conducted a series of experiments to comprehensively investigate this interaction, including surface pressure assessments, Brewster angle microscopy (BAM), and polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS). Our findings unequivocally demonstrate that sakuranetin interacts with these phospholipids, expanding the monomolecular films. Notably, regarding POPC, the presence of sakuranetin led to a reduction in stability and a decline in surface elasticity, which can likely be attributed to intricate molecular rearrangements at the interface. The visual evidence of aggregations in BAM images reinforces the interactions substantiated by PM-IRRAS, highlighting sakuranetin's interaction with the polar and nonpolar regions of POPC. However, it is worth noting that these aggregations do not appear to contribute significantly to the viscosity of the mixed film, and our investigations did not reveal any substantial hysteresis. In contrast, when examining POPE, we observed a minor reduction in thermodynamic stability, indicative of fewer rearrangements within the monolayer. This notion was further reinforced by the limited presence of aggregations in the BAM images. Sakuranetin also increased the rigidity of the lipid monolayer; nevertheless, the monolayer remained predominantly elastic, facilitating easy re-spreading on the surface, especially for the first lipid. PM-IRRAS analysis unveiled interactions between sakuranetin and POPE's polar and nonpolar segments, compellingly explaining the observed monolayer expansion. Taken together, our data suggest that sakuranetin was more effectively incorporated into the monomolecular layer of POPE, indicating that membranes comprised of POPC might exhibit a greater degree of interaction in the presence of this pharmacologically active compound.

Surfactant micellar induced aggregation control of an anionic fluorescent dye in Langmuir-Blodgett film

This work reports the formation of stable Langmuir monolayer of an anionic water soluble fluorescent dye 5(6)-carboxyfluorescein (abbreviated as CFS) by electrostatic interaction with a cationic monolayer. Formation of non-fluorescent H-dimeric sites of CFS molecules in Langmuir monolayer and Langmuir Blodgett films has been controlled by using cationic surfactant micelles of cetyltrimethylammonium bromide (CTAB). Thus the film can act as efficient fluorescence marker. Langmuir monolayer has been investigated by Surface Pressure versus Area per molecule (π-A) isotherm and in situ Brewster Angle Microscope (BAM) studies. Mono and multilayered Langmuir Blodgett films were characterized by using UV–vis absorption and steady state fluorescence spectroscopy.

Formation behavior of monolayers on the water surface of water-soluble thermoplastic and insoluble-thermosetting copolymers with hyperbranched units containing s-benzenetricarbamide cores

The formation and structure of Langmuir monolayers and Langmuir-Blodgett films were studied using water-soluble polymers, which have difficulty forming monolayers on the water surface, and polymers that are insoluble in all solvents. The network copolymers consisting of hyperbranched units with an s-benzenetricarbamide core used in this study can be freely controlled by azidation/non-azidation of both ends of the hard segment. The water-soluble copolymer, which exhibits the properties of a thermoplastic resin, can form a monolayer when spread on the water surface at a low temperature at which the solubility decreases. Even when the subphase temperature increased, no significant change in the monolayer behavior of the thermoplastic copolymer was observed. This behavior was attributed to the formation of an insoluble single-particle layer with hydrophilic groups facing inward on the water surface. The insoluble copolymer, which exhibits thermosetting properties, forms a tablet that floats on the water surface for an extended period. The surface pressure-time isotherms showed the formation of a monolayer from the tablet over time, and it was possible to measure the surface pressure-area isotherms by two-dimensional compression after a certain period of time.

Emerging specific selectivity towards mercury(II) cations in water through supramolecular assembly at interfaces

This work deals with the development of ultra-thin film nanosensors for selective and sensitive detection of toxic Hg2+ cations in aqueous media. 1,8-Bis[(2-aminoethyl)amino]anthraquinone D0 was functionalized by alkoxy groups of different length to prepare ligands D3 and D12 with linear arrangement of two polyamine receptors and two lipophilic alkyl chains. Chemosensor D0 only binds copper(II) and mercury(II) cations in water/methanol (1:1 v/v) solutions with no interference by other metal cations. The introduction of alkoxy groups to the anthraquinone scaffold, which are required to form Langmuir monolayers and ultra-thin films on solid supports, does not change the sensing properties of the anthraquinone D0. In contrast to systems without specific molecular order (i.e. solutions and drop-cast films), Langmuir monolayers and ultra-thin Langmuir-Blodgett films of alkoxy-substituted ligands selectively bind only mercury(II) cations, even in the presence of copper(II) ions and 10 other interfering cations. Selective binding of mercury(II) cations was confirmed by the UV–vis absorption and X-ray fluorescence spectroscopies. Thus, ultra-thin films, in which chemosensor molecules are assembled in highly ordered supramolecular systems, display a higher selectivity as compared to that of disordered molecular systems. Ultra-thin sensory film allows for the selective detection of the Hg2+ions in water when their concentration is exceeded 0.01 μM, which corresponds to the action level for Hg2+ ions in drinking water recommended by the U.S. Environmental Protection Agency. Chemosensor D12 is also suitable for the fabrication of electrochemical sensors for mercury(II) cations that show similar sensitivity.

Synthesis, Photophysics, and Langmuir Films of Polyfluorene/Permodified Cyclodextrin Polyrotaxanes.

In the present study, we investigated the effect of permodified 2,3,6-tri-O-trimethylsilyl β- and γ-cyclodextrin (TMS·β-CD, TMS·γ-CD) encapsulation on the optical, electrochemical, morphological, and supramolecular arrangements of a poly[2,7'-(9,9-dioctylfluorene-alt-2',7-fluorene)] PF copolymer. For this purpose, the photophysical properties and Langmuir monolayer formation of PF·TMS·β-CD and PF·TMS·γ-CD polyrotaxanes were investigated and compared with those of the reference PF. Surface pressure-area isotherms and Brewster angle microscopy studies indicated the capability of both polyrotaxanes to organize into larger and homogeneous 2D supramolecular assemblies at the air-water interface. The obtained results suggest that the presence of the surrounding TMS·β-CD and TMS·γ-CD macrocycles on the PF backbones leads to changes in the conformation and hydrophobicity of the film surfaces. Our investigation offers a method to assess the impact of TMS-CD encapsulation on the control of 2D monolayer formation, with particular attention on the generation of stable PF monolayers for organic electronic devices.

Evaluation of Non‐Ambiguous Critical Micelle Concentration of Surfactants in Relation to Solution Behaviors of Pure and Mixed Surfactant Systems: A Physicochemical Documentary and Analysis

AbstractCritical micelle concentration (CMC) is a fundamental physical parameter of surfactant aggregation in solution. The CMC is determined by different methods, tensiometry, conductometry, microcalorimetry, fluorimetry, and so on. However, it is known that though CMC is reported as a single value, in reality, micelle formation occurs over a narrow range of concentration for different experimental procedures produce different results. We shall discuss about a unique procedure of measuring correct CMC applicable to all potential methods used in practice. This is essential for the evaluation of thermodynamic properties of the micelle forming process in pure and mixed states in terms of solution theories. As we in this short documentary want to deal with various aspects of Milton Rosen's research—wherein we have also worked—a few other facets of surfactant chemistry research, besides the micelle formation, are also briefly discussed. In mixed surfactant systems, synergistic effects in various surfactant properties like detergency, foaming, solubilization, and so on are found whereas in some others non‐synergistic effects are observed. Dehydration of micelles with an increase in temperature or by the addition of hydrophilic substances may cause clouding to the system. Soluble amphiphilic systems produce Gibbs monolayer at the air/water interface; insoluble amphiphiles form Langmuir monolayers. A documentary of the above aspects will be herein presented and discussed. We mention that this article is neither an original research article nor a review article. This is a mixture of the two: a documentary of both original research and some review of our works presented in memory of Prof. Milton Rosen.

Features of formation of Langmuir monolayers of porphyrin derivatives on the surface of aqueous solutions of copper nanoparticles

Meso-aryl-substituted porphyrin monolayers were obtained by the Langmuir method depending on the aliquots applied to the water surface and the composition of the subphase. Regardless of the composition of the subphase (pure water or a solution with copper nanoparticles stabilized by surfactant) porphyrin compression isotherms showed the formation of monolayers until a film collapse state is reached. The presence in the subphase volume of copper nanoparticles stabilized by a surfactant (sodium dodecyl sulfate) contributed to the formation of a more stable porphyrin monolayer. A significant difference in the values of the surface potential at the end of porphyrin monolayer compression depending on the composition of the subphase is established. This fact is very promising in the context of creating film heterostructures with improved operational properties.

Synthesis and characterization of η6-p-cymene ruthenium(II) complexes containing alkyl- and methoxy-substituted triarylphosphines

Neutral Ru(II)-arene complexes [Ru(η6‐p-cymene)(PAr3)Cl2], PAr3 where Ar = 3,5-((CH3)3C)2C6H3–, 3,5-(CH3)2C6H3–, 4-CH3O-3,5-(CH3)2C6H2– and 4-CH3O-C6H4– were synthetized and fully characterized including single-crystal X-ray diffraction. The ligands have empirical logPow = 10.29, 7.38, 7.08, 5.43 (vs. PPh3 = 5.14). They have sufficiently low solubility to form Langmuir monolayers on water in accordance with overall molecular sizes. Density functional theory (DFT) calculations were performed to determine the molecular and electronic structures and to interpret the results of voltammetry and UV–Vis spectroscopy. Cytotoxicity assays were evaluated against MRC-5 (non-tumoral lung), A549 (lung cancer) and MDA-MB-231 (breast cancer) cell lines. The complexes with Ar = 3,5-((CH3)3C)2C6H3–, 4-CH3O-3,5-(CH3)2C6H2– and 4-CH3O-C6H4– show high cytotoxicity, whilst the first complex is inactive towards the (healthy) MRC-5 cell line, indicating a degree of selectivity.

Development of a Schottky barrier diode using molecular network of 1-alkyl-2-(arylazo) imidazole prepared by Langmuir–Blodgett technique

In this paper we report the photophysical and electrical characteristics of our synthesized imidazole derivative namely l-alkyl-2-(arylazo) imidazole (AAI) organized in Langmuir-Blodgett (LB) films towards the development of organic Schottky barrier diode (SBD). Presence of long alkyl chain in the molecule make it suitable for LB technology and may favour aggregations of the molecules in LB films under barrier compression. The interfacial properties of the formation of Langmuir monolayer of AAI at air-water interface have been studied by surface pressure versus area per molecule (π-A) isotherm and compressibility modulus. Hysteresis study of the isotherm confirmed the formation of stable monolayer of AAI molecular assemblies at air-water interface. The aggregation of AAI molecules in LB films is confirmed by Ultraviolet–visible (UV–vis) absorption, fluorescence emission spectroscopy and Atomic force microscopic (AFM) methods. AAI molecules also formed network type morphology in LB films due to their closure association and aggregations or cluster of molecules which were evidenced by AFM technique. The compression induced aggregations of AAI is reflected as broadened nature of monomeric absorption band along with the emergence of a new absorption band at longer wavelength side for LB film deposited at surface pressure of 25 mN/m. The optical absorption bands of AAI and the corresponding transitions between different electronic states have been simulated by density functional theoretical (DFT) analysis and is compared with the experimental results. Nonlinear behaviour of the current-voltage characteristics and various relevant electrical parameters of the LB film device at the interface of metal electrode (gold) satisfy the necessary conditions showing the properties of a Schottky barrier diode.

Photophysical and morphological properties of Langmuir–Blodgett films of benzothiadiazole derivatives

Organic semiconductors with extended π-conjugate systems have been extensively investigated to be implemented and improve optoelectronic devices. It is well known that benzothiadiazole (BTD) derivatives have interesting semiconductor properties that make them suitable materials for optoelectronic applications. In this work, the photophysical properties of 4 BTD with triphenylmethyl and triphenylsilyl derivatives in solution exhibited larger Stokes shifts, which can be attributed to the length and conjugation of these molecules. On the other hand, the quantum yields observed for these systems were larger than 0.5. In addition, the formation of Langmuir monolayers at the air–water interface with isotherms showing high collapse pressures around 60 mN/m, and stable compression–decompression cycles (hysteresis) were obtained. Langmuir–Blodgett films onto glass substrates were formed with these compounds by using the Z-type deposit with transfer ratios close to 1. In addition, high-fluorescence emission responses were observed for the BTD derivatives that did not contain silicon in their structure. Also, using scanning electron and atomic force microscopies, regular surface morphologies were observed for the silicon-less compounds, but higher roughnesses and fiber-like structures for the other films. From these results, these BTD films can be potential candidates to be employed in photoelectronic applications.

Thermally Stable Nitrothiacalixarene Chromophores: Conformational Study and Aggregation Behavior.

Achieving high thermal stability and control of supramolecular organization of functional dyes in sensors and nonlinear optics remains a demanding task. This study was aimed at the evaluation of thermal behavior and Langmuir monolayer characteristics of topologically varied nitrothiacalixarene multichromophores and phenol monomers. A nitration/azo coupling alkylation synthetic route towards partially O-substituted nitrothiacalixarenes and 4-nitrophenylazo-thiacalixarenes was proposed and realized. Nuclear magnetic resonance (NMR) spectroscopy and X-ray diffractometry of disubstituted nitrothiacalix[4]arene revealed a rare 1,2-alternate conformation. A synchronous thermal analysis indicated higher decomposition temperatures of nitrothiacalixarene macrocycles as compared with monomers. Through surface pressure/potential-molecular area measurements, nitrothiacalixarenes were shown to form Langmuir monolayers at the air–water interface and, through atomic force microscopy (AFM) technique, Langmuir–Blodgett (LB) films on solid substrates. Reflection-absorption spectroscopy of monolayers and electronic absorption spectroscopy of LB films of nitrothiacalixarenes recorded a red-shifted band (290 nm) with a transition from chloroform, indicative of solvatochromism. Additionally, shoulder band at 360 nm was attributed to aggregation and supported by gas-phase density functional theory (DFT) calculations and dynamic light scattering (DLS) analysis in chloroform–methanol solvent in the case of monoalkylated calixarene 3. Excellent thermal stability and monolayer formation of nitrothiacalixarenes suggest their potential as functional dyes.

Langmuir and Langmuir-Blodgett Films of Poly[(9,9-dioctylfluorene)-co-(3-hexylthiophene)] for Immobilization of Phytase: Possible Application as a Phytic Acid Sensor.

In this work, the copolymer poly[(9,9-dioctylfluorene)-co-(3-hexylthiophene)] was employed as a matrix for immobilizing phytase, aiming at the detection of phytic acid. The copolymer was spread on the air-water interface forming Langmuir monolayers and phytase adsorbed from the aqueous subphase. The interactions between the copolymer and the enzyme components were investigated with surface pressure and surface potential-area isotherms, Brewster angle microscopy, and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS). The enzyme could be incorporated in the monolayers from the aqueous subphase, expanding the copolymer films and maintaining its secondary structure. The polymeric films presented a morphological heterogeneous pattern at the air-water interface because of the ability of their chains to fold and entangle, causing inherent defects in the organization as well as unbalanced lateral distribution at the air-water interface because of the formation of aggregates. The interfacial films were transferred to solid supports as Langmuir-Blodgett films and characterized by PM-IRRAS and scanning electronic microscopy, which showed not only the co-transfer of the enzyme but also the maintenance of their heterogeneous morphological pattern. The enzymatic activity of the blended film was analyzed by UV-vis spectroscopy and allowed the estimation of the value of the Michaelis constant (13.08 mM), demonstrating the feasibility of the system to selectively detect phytic acid for biosensing purposes.

Precise and instrumental measurement of thermodynamics and kinetics of froth flotation by langmuir-blodgett technique

Froth flotation is most common means in mineral separation, and the in-situ measurement of flotation is of significance. However there were no instrumental means of measuring kinetics and thermodynamics for this process up to date. Herein, for the first time a facile method was developed by using Langmuir-Blodgett (LB) technique to get precise recording of kinetics and thermodynamics for adsorption process of Langmuir hybrid layer at the air/water interface. The formation of hybrid Langmuir monolayer was assumed to simulate the adsorption of mineral particles by frother/collector bubbles in the micro-flotation although this was a semi-static adsorption process. The kinetic parameters including time constant (τ1/e, 32.0∼139.0 s) and adsorption rate constant (k, 0.0315∼0.00718 s−1) were precisely determined according to surface pressure vs. time (π-t) plots of Langmuir monolayer which consisted of floated minerals particles and collector molecules. The thermodynamic data such as partition coefficient (Kd, 0.221−0.339), Gibbs free energy of adsorption ΔG (2.68∼3.74 kJ mol−1), and minimum dosages of collector molecules (potassium butylxanthate) were derived from the surface pressure vs. molecular area (π-A) isotherms. Taking the major mineral of pyrite with minor of dolomite and quartz as a froth flotation model, the recovery yield of concentrate pyrite obtained from LB technique was found in good agreement with the common tests used micro-flotation, suggesting the consistency of the new-developed LB method in predicting kinetics and thermodynamics for froth flotation.

Use of a theoretical prediction method and quantum chemical calculations for the design, synthesis and experimental evaluation of three green corrosion inhibitors for mild steel

Three phenylmethanimine derivatives (Schiff bases) were designed after a theoretical prediction of their corrosion inhibition efficiencies and a corroboration through the use of quantum chemical calculations. The molecules were then prepared using a classical condensation reaction between aldehydes and amines but taking in account the tenets of green chemistry. Their application as corrosion inhibitors for ASTM A36 steel in 1 mol L−1 hydrochloric acid media was explored by means of a weight loss analysis, electrochemical tests and a surface morphology analysis to physically evaluate the metallic sacrifice surfaces used. The results of the electrochemical tests revealed that the three compounds have a good anti-corrosion capacity and act as mixed-type corrosion inhibitors. In addition, cross-checking the data from weight loss analysis and electrochemical tests confirm Langmuir monolayer formation theory. The corrosion inhibition efficiencies found range between 83.5 and 95.6%.

Isothermal measurements of a Langmuir monolayer of a non-polar fluorocarbon chain molecule

Traditionally Langmuir monolayers and lipids bilayers (including cell membranes) on water interfaces are made of amphiphilic molecules with both polar hydrophilic and non-polar hydrophobic parts. It has been discovered that non-polar fluorocarbon chain molecules without the polar hydrophilic part, F(CF2)20F, can also form Langmuir monolayers on water. Here we report the surface pressure vs. area isotherm measurements of a F(CF2)20F film on water, which show the film’s maximum compression modulus (greatest resistance to lateral compression) at about 30 Å2/molecule, independent of the compression speed, like the Langmuir monolayers of long chain saturated fatty acids do. The cross-section area of the fluorocarbon chain is 28.1 Å2 in 3-D crystalline F(CF2)20F. Our measurements confirm the formation of a Langmuir monolayer by F(CF2)20F, a non-polar fluorocarbon chain molecule. We observed a general trend that greater the lateral compression speed, lower the maximum compression modulus, lower the resistance to lateral compression. Nicholas Sheetz and Clayton Smith are grateful to financial support from the National Science Foundation through the SOARS Research Fellowship at Shepherd University.

Isothermal measurements of a Langmuir monolayer of a non-polar fluorocarbon chain molecule.

Traditionally Langmuir monolayers and lipids bilayers (including cell membranes) on water interfaces are made of amphiphilic molecules with both polar hydrophilic and non-polar hydrophobic parts. It has been discovered that non-polar fluorocarbon chain molecules without the polar hydrophilic part, F(CF2)20F, can also form Langmuir monolayers on water. Here we report the surface pressure vs. area isotherm measurements of a F(CF2)20F film on water, which show the film’s maximum compression modulus (greatest resistance to lateral compression) at about 30 Å2/molecule, independent of the compression speed, like the Langmuir monolayers of long chain saturated fatty acids do. The cross-section area of the fluorocarbon chain is 28.1 Å2 in 3-D crystalline F(CF2)20F. Our measurements confirm the formation of a Langmuir monolayer by F(CF2)20F, a non-polar fluorocarbon chain molecule. We observed a general trend that greater the lateral compression speed, lower the maximum compression modulus, lower the resistance to lateral compression.Nicholas Sheetz and Clayton Smith are grateful to financial support from the National Science Foundation through the SOARS Research Fellowship at Shepherd University.

Molecular Information on the Potential of Europium Complexes for Local Recognition of a Nucleoside-Based Drug by Using Nanostructured Interfaces Assembled as Langmuir-Blodgett Films.

The production of nanostructured materials for biological and medical applications may be applied toward the conjugation of adequate substances to boost the stimulus response of sensors and diagnostic probes. In this sense, Langmuir-Blodgett films constituted of bioinspired and biomimetic materials have attracted attention because of the ease of manipulation of the molecular architecture. In this paper, we employed a nucleoside-based drug, which was linked with a sterol hydrophobic moiety (3',4'-acetonide-uridine-succinate-cholesterol conjugate) to provide it an amphiphilic character. The drug was spread on the air-water interface, alone or mixed with stearic acid, forming Langmuir monolayers, and the complex Eu(tta)3(H2O)2 was incorporated in the drug-containing monolayer. Interactions at the air-water interface between stearic acid, the drug, and the europium complex were then investigated with tensiometry, surface potential, infrared spectroscopy, and Brewster angle microscopy. The Langmuir films were transferred to solid supports as Langmuir-Blodgett films, which presented luminescent properties that could be tuned according to the molecular architecture. We believe that these results can serve as a novel approach to characterize and assemble materials organized in the molecular scale for medical applications.