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Recent advancements in medical science have ushered in the era of "Personalized Medicine," which tailors treatments to individual genetics, lifestyle, and environmental factors. A cornerstone of this approach is continuous monitoring and adjustment of treatment regimens to optimize effectiveness while minimizing side effects. In therapeutic drug monitoring (TDM), crucial for drugs like doxorubicin (DOX) with severe side effects, traditional methods such as spectrofluorimetry and chromatography are utilized, but they suffer from cost and complexity issues. Biosensors, especially those leveraging Localized Surface Plasmon Resonance (LSPR) and surface-enhanced Raman spectroscopy (SERS), offer a promising alternative. This study focuses on developing a cost-effective plasmonic biosensor using gold nanoislands semiembedded in a glass substrate. The LSPR platform, based on gold nanoislands (Au NIs) with an average diameter of 23 nm, offers a rapid method for ultrasensitive, label-free detection of DOX in biological fluids up to the nanomolar range, even in diluted (1:10) and undiluted blood serum samples from cancer patients receiving the drug. The method capitalizes on the extraordinary adhesion between the nanoislands and the glass matrix, preserving plasmon integrity while enhancing the electric field surrounding the nanoislands for improved sensitivity. Moreover, by exploiting nanoislands with Au/Al2O3 core/shell structures with an average diameter and gap of about 70 and 7 nm, respectively, highly efficient SERS-active platforms are created, enabling the detection of ultralow DOX concentrations down to picomolar range, where the LSPR system is insensitive. The combined use of both systems enables the detection of DOX across a broad range, from low to high nanomolar concentrations, in biological fluids. This integration of semiembedded nanoislands presents a scalable and multifunctional approach suitable for point-of-care diagnostics, offering reproducible and stable characteristics over time. [ABSTRACT FROM AUTHOR]

Coulomb interactions are used between cationic fullerene derivatives at the water surface and anionic porphyrins dissolved in the water subphase to deposit monolayer dyad films. The films resulting from the interaction are transferred through the Langmuir-Schafer method, that is, horizontal lifting of the electrostatistically induced donor-acceptor systems.

The structural and spectroscopic properties of ethane-bridged Zn porphyrin dimers in Langmuir-Schafer (LS) thin films are investigated. Diluting ethane-bridged Zn porphyrin dimers in arachidic acid minimizes the porphyrin aggregation and with ethane-bridged Zn porphyrin dimers exhibiting the anti conformation the LS films become photoresponsive, showing fluorescence emission and triplet-triplet transient absorption.

The Langmuir-Schafer (LS) technique (horizontal lifting) were used to deposit thin films of a newly synthesized iron(III) porphyrazine, LFeOESPz (L = ClEtO, OESPz = ethylsulfanylporphyrazine), on indium tin oxide (ITO) or gold substrates. The results could be used in application of the target iron(III) porphyrazines in electrocatalysis and in the field of protic sensors.

Preparation and characterization of films novel amphiphilic complex, deposited through a modification of the LB technique, and the horizontal lifting or Langmuir-Schafer (LS) method is discussed. In this work homogeneous, densely packed LS films of a novel amphiphilic Ru(II) complex are obtained.

A Pz derivative, 2,3,7,8,12,13,17,18-Octakis(methylthio)-5,10,15,20-21H,23H-porphyrazine, H2OMTPz, is used to prepare thin films by the Langmuir-Shafer technique. The main feature resulting from the research is the profoundly different molecular organization at the air-water interface and onto hydrophobic quartz and glass substrate.

Constructing the film of poly(2,5-dioctyloxy-1,4-phenylene-alt-2,5-thienylene) is synthesized and behavior of this thin film at the air-water interface is studied by microscopy and reflection spectroscopy. The floating films are transferred by the Langmuir-Schafer (horizontal lifting) method onto various substrates.

Spiramycin is a macrolide antibiotic and antiparasitic that is used to treat toxoplasmosis and various other infections of soft tissues. In the current study, we evaluated the effects of α-cyclodextrin, β-cyclodextrin, or methyl-β-cyclodextrin supplementation to a synthetic culture medium on biomass and spiramycin production by Streptomyces ambofaciens ATCC 23877. We found a high stimulatory effect on spiramycin production when the culture medium was supplemented with 0.5% (w/v) methyl-β-cyclodextrin, whereas α-cyclodextrin or β-cyclodextrin weakly enhanced antibiotic yields. As the stimulation of antibiotic production could be because of spiramycin complexation with cyclodextrins with effects on antibiotic stability and/or efflux, we analyzed the possible formation of complexes by physical-chemical methods. The results of Job plot experiment highlighted the formation of a nonhost@guest complex methyl-β-cyclodextrin@spiramycin I in the stoichiometric ratio of 3:1 while they excluded the formation of complex between spiramycin I and α- or β-cyclodextrin. Fourier-transform infrared spectroscopy measurements were then carried out to characterize the methyl-β-cyclodextrin@spiramycin I complex and individuate the chemical groups involved in the binding mechanism. These findings may help to improve the spiramycin fermentation process, providing at the same time a new device for better delivery of the antibiotic at the site of infection by methyl-β-cyclodextrin complexation, as it has been well-documented for other bioactive molecules., Competing Interests: The authors declare no competing financial interest.

A porous collagen-based hydrogel scaffold was prepared in the presence of iron oxide nanoparticles (NPs) and was characterized by means of infrared spectroscopy and scanning electron microscopy. The hybrid scaffold was then loaded with fluorescein sodium salt as a model compound. The release of the hydrosoluble species was triggered and accurately controlled by the application of an external magnetic field, as monitored by fluorescence spectroscopy. The biocompatibility of the proposed matrix was also tested by the MTT assay performed on 3T3 cells. Cell viability was only slightly reduced when the cells were incubated in the presence of the collagen-NP hydrogel, compared to controls. The economicity of the chemical protocol used to obtain the paramagnetic scaffolds as well as their biocompatibility and the safety of the external trigger needed to induce the drug release suggest the proposed collagen paramagnetic matrices for a number of applications including tissue engeneering and drug delivery.

Single-walled carbon nanotubes (SWCNTs) were suspended in 1,2-dichloroethane by noncovalent functionalization with a low-band-gap conjugated polymer 1 alternating dialkoxyphenylene-bisthiophene units with benzo[c][2,1,3]thiadiazole monomeric units. The suspended 1/SWCNT blend was transferred onto different solid substrates by the Langmuir-Schaefer deposition method, resulting in films with a high percentage of aligned nanotubes. Photoelectrochemical characterization of 1/SWCNT thin films on indium-tin oxide showed the benefits of SWCNT alignment for photoconversion efficiency.

The ability of microorganisms to adhere to abiotic surfaces and the potentialities of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy have been exploited to study protonation and heavy metal binding events onto bacterial surfaces. This work represents the first attempt to apply on bacteria the recently developed method known as perfusion-induced ATR-FTIR difference spectroscopy. Such a technique allows measurement of even slight changes in the infrared spectrum of the sample, deposited as a thin layer on an ATR crystal, while an aqueous solution is perfused over its surface. Solutions at different pH have been used for inducing protonation/deprotonation of functional groups lying on the surface of Rhodobacter sphaeroides cells, chosen as a model system. The interaction of Ni(2+) with surface protonable groups of this microorganism has been investigated with a double-difference approach exploiting competition between nickel cations and protons. Protonation-induced difference spectra of simple model compounds have been acquired to guide band assignment in bacterial spectra, thus allowing identification of major components involved in proton uptake and metal binding. The data collected reveal that carboxylate moieties on the bacterial surface of R. sphaeroides play a role in extracellular biosorption of Ni(2+), establishing with this ion relatively weak coordinative bonds.

This article reports on an extensive investigation on a functionalized phthalocyanine, namely, copper(II) tetrakis-(isopropoxy-carbonyl)-phthalocyanine (TIPCuPc). The self-association of the molecules is extensively described in solution in different solvents (DMSO, DMF, CHCl(3), pyridine) by means of UV-vis steady state spectroscopy at the air/water interface by Brewster angle microscopy (BAM) and in thin films by using atomic force microscopy (AFM). We investigated the morphology of TIPCuPc as thin film by evaluating different factors: temperature, solvent, concentration, transferring procedure (spin-coating and Langmuir-Schafer technique), and nature of the substrate (mica and quartz). The behavior of the molecules under UV light irradiation and their thermal stability were studied as well. Such a detailed study can allow a suitable processing of this phthalocyanine derivative for future applications. Here the photoelectrochemical activity of the phthalocyanine was investigated when suitably combined as sensitizer with rodlike TiO(2) nanocrystals (NCs) in hybrid junctions integrated in a photoelectrochemical cell.

Aggregation behavior of unsubstituted copper porphyrazine (CuPaz) on the water surface was studied by analysis of compression curves, Brewster angle microscopy (BAM), and optical spectroscopy. The structure and stability of the CuPaz aqua aggregates in the floating layers are determined by hydration degree that depends on initial surface concentration and surface pressure. Langmuir-Schaefer (LS) films of CuPaz were prepared by deposition of the variously structured floating layers and studied by X-ray scattering technique and optical spectroscopy. Stable and labile structures were detected and compared with the floating CuPaz aqua aggregates. Conditions of formation of the stable four-stacked nanoaggregates in LS films were determined. A model comprising both nucleation of CuPaz on the water surface and structural transformations in the solid films is proposed.

Langmuir-Blodgett films containing meso,meso'-buta-1,3-diyne-bridge Cu(II) octaethylporphyrin dimer have been deposited with the aim of carrying out a thermally stimulated current (TSC) investigation. This characterization was obtained upon cooling samples irradiated by light and others without irradiation: in this way TSC curves have been registered in the temperature range of 100-300 K. Analysis of experimental data has been performed through the application of three different approaches: the initial rate, the heating rate, and Chen's methods. In particular, a trap center at about 0.38 eV has been evidenced and the three different methods have given results in close accordance.