Abstract Target molecules adsorbed onto metallic nanoparticles can have their Raman and/or fluorescence signals enhanced, leading to the called surface-enhanced [resonance] Raman scattering (SE[R]RS) or surface-enhanced fluorescence (SEF). Here we have applied Au nanorods (AuNRs) coated with a surfactant bilayer leading to a positive surface charge to investigate the role played by these AuNRs in colloidal suspension on SERRS and SEF effects of charged molecules. In the case of the anionic nickel (II) tetrasulfonated phthalocyanine (NiTsPc), besides achieving SERRS with an enhancement factor (EF) of ca. 105, the AuNRs allowed the analytical application of the SERRS effect for the NiTsPc between 8.3x10-6 and 4.0x10-5 mol L-1. The limit of detection of 4.8x10-7 mol L-1 (at 752 cm-1) and 1.3x10-6 mol L-1 (at 1338 cm-1) was found. In the case of the cationic methylene blue, the SEF effect was achieved reaching an EF of ca. 10. Besides, fundamental discussions are carried out considering the results presented here.

SUMMARY: The objective of this study was to evaluate the effects of growth hormone (GH) and muscle strength training (ST) on the composition of bone tissue of Wistar rats through Raman spectroscopy. In total, 40 male rats were randomly distributed into four groups: (N = 10) control (C), control with the application of GH (GHC), strength training (T), and strength training with the application of GH (GHT). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50 % of body weight and duration of four weeks. GH was applied at a dose of 0.2 IU / kg in each animal three times a week and every other day. After four weeks, the animals were euthanized and the right femurs collected for analysis of the bone structure. Raman spectroscopy (ER) was used to observe the following compounds from their respective bands: Calcium Carbonate-Triglycerides (fatty acids) 1073 cm-1, Collagen type I 509 cm-1, Bone-DNA Phosphate (Protein) 589 cm-1, Phosphate Phospholipids 1078 cm-1. For the statistical analysis, the Shapiro-Wilk and ANOVA One-Way variance analysis normality tests were performed, followed by the Tukey post-test. The results showed an increase in the concentrations of calcium carbonate-triglycerides (fatty acids), type I collagen, bone phosphate-DNA (protein), and phosphate phospholipids in all experimental groups, with or without ST and/or GH , But only the isolated training group differed significantly from the control group (P <0.05). It was concluded that all treatments could promote bone tissue gain, however, only the T group demonstrated a significant difference in the mineral compounds analyzed.

RESUMEN: El objetivo del estudio fue avaluar el efecto de la aplicación de la hormona del crecimiento (GH) y entrenamiento de la fuerza muscular (EF) en la composición del tejido óseo de ratas Wistar a partir de la espectroscopía Raman. Fueron utilizadas 40 ratas machos distribuidas de forma aleatoria en cuatro grupos (n=10): control (C), control y aplicación de GH (GHC), entrenamiento de la fuerza muscular (EF) y entrenamiento de la fuerza muscular y aplicación del GH (GHE). El entrenamiento fue consistió en cuatro series de 10 saltos acuáticos, realizados tres veces en la semana, con sobrecarga correspondiente a 50 % de la masa corporal y durante cuatro semanas. El GH fue aplicado en la dosificación de 0,2 UI/kg en cada animal, tres veces en la semana y en días alternados. Después de cuatro semanas, los animales fueran eutanasiados y retirados los fémures derechos para un análisis de la estructura ósea. La espectroscopía Raman fue utilizada para observar los siguientes compuestos a partir de las respectivas bandas: Carbonato de Calcio-Triglicéridos (ácidos grasos) 1073 cm-1, Colágeno Tipo I 509 cm-1, Fosfato Óseo-DNA (Proteína) 589 cm1, Fosfato Fosfolípidos 1078 cm-1. Para el análisis estadístico, fueron realizadas las pruebas Shapiro-Wilk y el análisis de variancia ANOVA One-Way, seguida de test post hoc de Tukey. Los resultados revelaran aumento de la concentración de Carbonato de Calcio-Triglicéridos (ácidos grasos), Colágeno Tipo I, Fosfato Óseo- DNA (Proteína), Fosfato Fosfolípidos en todos los grupos experimentales, asociados o no a la realización del EF y/o aplicación del GH. Además, solamente el grupo EF mostró diferencia significativa del grupo C (p<0,05). Es posible concluir que todos los tratamientos mostraran aumentos en el tejido óseo, sin embargo, solamente el grupo T demostró una diferencia significativa en los compuestos minerales analizados.

The analysis of supramolecular arrangement is essential to understand the role of this key factor on the optical and electrical properties of organic thin films. In this work, thin solid films of bis(phenethylimido) perylene (PhPTCD) fabricated using physical vapor deposition (PVD) technique (thermal evaporation), deposited simultaneously onto different substrates (Ag mirror, Ge, and quartz plates) contingent on the characterization technique. The main objective is to study the PhPTCD supramolecular arrangement and the thermal stability of this arrangement in PVD films. The ultraviolet-visible absorption reveals a controlled growth of the PVD films, and the micro-Raman scattering data show that the PhPTCD molecule is not thermally degraded in the conditions of these experiments. The microscopy also shows a homogeneous morphological surface of the PVD film at macro and micro scales, with molecular aggregates at nanoscale. Besides, the PVD film roughness does not follow substrate roughness. The X-ray diffraction indicates a crystalline structure for PhPTCD powder and an amorphous form for PhPTCD PVD film. The infrared absorption spectroscopy points to a preferential flat-on organization of the molecules in the PVD films. In addition, the annealing process (200 ºC for 20 minutes) does not affect the supramolecular arrangement of the PhPTCD PVD films.

The supramolecular structure of organic thin films is a key factor in their optical and electrical properties and, consequently, in the technological applications involving organic electronic. Here, thin films of a perylene derivative, the bis butylimido perylene (BuPTCD), were produced by vacuum thermal evaporation (PVD, physical vapor deposition). The main objective is to investigate the supramolecular structure of the BuPTCD in these PVD films, which implies to control their thickness at nanometer scale and to determine their molecular organization, morphology at micro and nanometer scales and crystallinity. The ultraviolet-visible absorption reveals a uniform growth of the PVD films. The optical and atomic force microscopy images show a homogeneous surface of the film at micro and nanometer scales, respectively. The X-ray diffraction indicates that both powder and PVD film are in the crystalline form. Complementary, a preferential head-on orientation of the molecules in the PVD films is determined via infrared absorption spectroscopy. Besides, the annealing process (200oC) did not affect the molecular organization of the PVD films, revealing a thermal stability of the BuPTCD molecules within the PVD films. Through DC electrical measurements, an electrical conductivity of 7.45x10-10 S/m was determined for BuPTCD PVD films onto Au interdigitated electrodes (IDE-structured devices), which can be enhanced, under illumination, by two orders of magnitude (photoconductivity effect). As proof-of-concept, the IDE-structured devices are tested as gas sensor for trifluoroacetic acid.

Thermal inkjet-printing of copper tetrasulfonated phthalocyanine (CuTsPc) films containing polyvinyl alcohol (PVA) plasticizer were used to fabricate flexible metal-insulator-semiconductor (MIS) capacitors using anodic aluminum oxide (Al2O3) as the insulating layer. The Al2O3 layer and printed CuTsPc+PVA films were characterized individually and in a MIS structure by electrical impedance spectroscopy. Capacitance-frequency and capacitance-voltage measurements revealed distinct contributions from CuTsPc and PVA on the device electrical response. From these measurements the semiconductor charge carrier mobility, ∝, of 1.22x10- 4 cm² V- 1 s- 1 and the doping density, N A, of 3.1x10(16) cm- 3 were calculated. It was observed a low-frequency electrical response, which was attributed to diffusional processes within the printed film arising from Na+ ions dissociated from the CuTsPc molecule. A simple equivalent circuit model was proposed to take this effect into account. Finally, the results shown here demonstrate the possibility to produce flexible organic electronic devices exploiting the semiconducting properties of water-soluble CuTsPc molecules using low-cost commercial printers.

A study is reported on Langmuir and Langmuir-Blodgett (LB) films obtained by adding different percentages of stearic acid (SA) to poly(3-octylhiophene) (P3OT). Surface pressure - mean molecular area (π - A) isotherms, ultraviolet-visible (UV-Vis) absorption spectrum, atomic force microscope (AFM) and dc electrical measurements have been used for characterization. From π - A isotherms, the area per monomer for condensed films (of SA) increased according to P3OT amount. Good transfer ratios were obtained for LB deposition from P3OT/SA films with higher percentage of SA. LB films revealed linear growth as monitored by UV-Vis absorption spectra. Electrical characterization showed higher conductivity for LB film with 54 wt.% of SA. AFM images of the same film revealed high roughness and presence of large size agglomerates. Finally, interdigitated electrodes (IDE) coated with P3OT/SA LB films showed to be sensitive to the presence of volatile organic compounds.