Marcela Dendisová

Study of plasmonic nanoparticles interactions with skin layers by vibrational spectroscopy

Graphical abstract Figure. No Caption available. Abstract 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.

Synthesis and deposition of a Tröger’s base polymer on the electrode surface for potentiometric detection of a neuroblastoma tumor marker metabolite

The development of novel diagnostic tools is a primary goal in bioanalytical chemistry. Here we report the synthesis of Trögers base functionalized with amino- and coumarin-units designed as a monomeric unit for the development of an electrochemical cancer sensor. The synthesized receptor was deposited onto a conducting support using electrochemical polymerization, characterized spectroscopically and tested potentiometrically towards metabolites used as tumor markers of neuroblastoma.

The Eighth Central European Conference “Chemistry towards Biology”: Snapshot

The Eighth Central European Conference “Chemistry towards Biology” was held in Brno, Czech Republic, on August 28–September 1, 2016 to bring together experts in biology, chemistry and design of bioactive compounds; promote the exchange of scientific results, methods and ideas; and encourage cooperation between researchers from all over the world. The topics of the conference covered “Chemistry towards Biology”, meaning that the event welcomed chemists working on biology-related problems, biologists using chemical methods, and students and other researchers of the respective areas that fall within the common scope of chemistry and biology. The authors of this manuscript are plenary speakers and other participants of the symposium and members of their research teams. The following summary highlights the major points/topics of the meeting.

SERS study of riboflavin on green-synthesized silver nanoparticles prepared by reduction using different flavonoids: What is the role of flavonoid used?

Spectroscopy of surface-enhanced Raman scattering (SERS) is nowadays widely used in the field of bio-science and medicine. These applications require new enhancing substrates with special properties. They should be non-toxic, environmentally friendly and (bio-) compatible with examined samples. Flavonoids are natural antioxidants with many positive effects on human health. Simultaneously, they can be used as reducing agent in preparation procedure of plasmonic enhancing substrate for SERS spectroscopy. The best amplifiers of Raman vibrational spectroscopic signal are generally silver nanoparticles (AgNPs). In this study, several flavonoids (forming a logical set) were used as reducing agent in AgNPs preparation procedures. Reactivity of 10 structurally arranged flavonoids (namely flavone, chrysin, apigenin, luteolin, tricetin, 3-hydroxyflavone, galangin, kaempferol, quercetin and myricetin) was compared and SERS-activity of prepared AgNPs was tested using model analyte riboflavin. Riboflavin was detected down to concentration 10-9mol/l.

Copper–gold sandwich structures on PE and PET and their SERS enhancement effect

A Surface Enhanced Raman Spectroscopy (SERS) system with the coupling between surface plasmon polaritons (SPPs) supported by a gold grating and localized surface plasmons (LSPs) excited on grafted copper nanoparticles (CuNPs) was designed and characterized. The excitation of copper nanoparticles–molecules–gold layer sandwich structures was studied under 633 nm wavelength irradiation. Rhodamine 6G (R6G) molecules were added onto SERS substrates and located above and between the CuNPs. Prepared samples were studied by several experimental techniques: goniometry, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrokinetic analysis. Aging of the modified PE and PET was accompanied by an increase in the contact angle, which was due to a reorientation of the molecular polar segments produced during the plasma treatment. XPS and zeta potential measurements indicated that the thiols were chemically bonded to the gold coated polymer surfaces and that the thiols mediate subsequent grafting of Cu nanoparticles. Both XPS and EDS analyses revealed that a higher concentration of grafted copper nanoparticles was achieved on the PET substrate. EDS showed that Cu nanoparticles are homogeneously distributed over the whole polymer surface. The enhancement factor was higher for PE (1.7 × 103) compared to PET (0.9 × 102).

Preparation of surfaces of composite samples for tip based micro-analyses using ion beam milling

Ion beam milling, as a method of surface design for tip analytical techniques, was explored. A sample of clay, embedded in a resin, was treated by the ion beam and allowed AFM (a typical tip technique) to be successfully applied. The method is suitable for advanced tip analyses based on AFM, like TERS or SNOM, and for samples that are not possible to prepare by standard mechanical methods. The approach can be useful for characterisation of the surfaces of many different types of materials in versatile applications such as catalysis, corrosion science or advanced material characterisation.

The use of infrared spectroscopic techniques to characterize nanomaterials and nanostructures: A review

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.