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Interactions between molecules are fundamental in biology. They occur also between amyloidogenic polypeptides that are associated with different amyloid diseases, which makes it important to study their interactions. However, addressing such research questions with imaging techniques is hindered by the problem to distinguish different polypeptides without adding artificial probes for detection. Here we present a new method for this purpose. We show that 13C-labeling can be used to distinguish peptides in nanoscale images of their infrared absorption, even when they have similar secondary structure. We studied different aggregation states of the amyloid-β peptide (Aβ) and its interaction with an inhibitory cell-penetrating peptide (NCAM1-PrP) using scattering-type scanning near field microscopy. Labeled and unlabeled peptides could be discriminated by comparing images of the optical phase taken at wavenumbers characteristic for either the labeled or the unlabeled peptide. NCAM1-PrP seems to be able to dissolve or coat existing Aβ fibrils because "naked" Aβ fibrils are not detected after mixing.

The original goal of this study was the employment of surface-enhanced Raman spectroscopy (SERS) for the analysis of real cocaine samples (containing adulterants) on composite Au-TiO2 nanomaterials to achieve low detection limits suitable for the analysis of illicit drugs and controlled substances and to exploit the photodegradation activity of TiO2 to recycle the SERS substrate for repeated analyses. The photodegradation (self-cleaning) effects of the Au-TiO2 composite nanomaterials by ultraviolet (UV) radiation are known. These effects were investigated on large-area SERS substrates immersed in the TiO2 nanoparticle aqueous suspension. The cocaine samples were measured on electrochemically gold-plated platinum targets. Surprisingly, the intensity of SERS spectra of the pure cocaine did not change after immersion in a suspension of TiO2 under UV irradiation. However, for some real cocaine samples, the overall intensity of the SERS spectra was even higher after the treatment by TiO2 and UV radiation as co...

The transdermal transmission of model substance on the pigskin samples was investigated using the attenuated total reflection (ATR) technique of infrared (IR) spectroscopy. The collected vibrational spectroscopic data were evaluated by multidimensional statistical methods as principal component analysis (PCA), linear discriminant analysis (LDA) and partial least squares (PLS) regression which enable detection of individual substances in the skin, their identification and mutual differentiation. Gallic acid (GA), a natural phenolic anti-oxidant with many potential healing properties suitable e.g. for atopic dermatitis treatment, was used as an analyte. Effect of GA on the skin surface was examined for four different solvents namely ethanol (EtOH), methanol (MeOH), dimethyl sulfoxide (DMSO) and ultrahigh purity water (H 2 O). Moreover, the effects of temperature related to GA solubility in H 2 O were investigated. During the series of experiments, nonsystematic changes of untreated skin samples were observed; while systematic changes are evident after the skin treatment. The systematic effects correspond to structural changes of the skin constituents during substance penetration.

The healing effects of silver and gold nanoparticles (AgNPs, AuNPs) are already known from ancient times. In addition considering to their antibacterial and anti-inflammatory effects speculations are being lead with respect to these nanoparticles (NPs) also about enhancement of skin penetration properties. In this work the interactions of pig skin (PS) layers and ointments with additions of AgNPs or AuNPs prepared by standard procedures and also by "green" synthesis in a different weight proportion by vibrational spectroscopy were studied. Spectra of untreated skin and skin treated by pure ointment were measured, as well as by ointment modified by vitamins without addition of NPs or with different proportion of NPs. Kinetics of interactions of modified ointments with skin was monitored during two hours with a five-minutes interval between each two consecutive measurements. The obtained series of spectra were analyzed by multivariate statistical methods namely Partial Least Squares (PLS), Principal Component Analysis (PCA) and Soft Independent Modelling of Class Analogy (SIMCA) which revealed observation of spectral changes in time-dependent spectra and variations of the peak intensity ratios. The study showed that the effects of quantity and type of NPs on skin penetration characteristics are evident.

The original goal of this study was the employment of surface-enhanced Raman spectroscopy (SERS) for the analysis of real cocaine samples (containing adulterants) on composite Au-TiO

Recent advances in nanotechnology have opened a lot of new possibilities for nanomaterials application in wide variety of industrial, pharmaceutical, medicinal and environmental applications. This review aims to description of various Fourier Transform Infrared (FTIR)-based spectroscopic techniques suitable to characterize (i) different types of nanomaterials and (ii) various macroscopic samples at their nanoscale. In the introductory section, nanomaterials are classified according to their crucial properties, i.e. chemical composition, size and surface morphology. Application of traditional FTIR techniques, such as Attenuated Total Reflection (ATR), Diffuse Reflection (DRIFT) and infrared micro (spectro)scopy, for characterization of nanomaterials and nanostructures is compared with novel optical nanoscopic techniques derived from scanning probe microscopy which enable to overcome the diffraction limit and to characterize nanomaterials at molecular scale.