Drug-Based Gold Nanoparticles Overgrowth for Enhanced SPR Biosensing of Doxycycline

In clinical chemistry, frequent monitoring of drug levels in patients has gained considerable importance because of the benefits of drug monitoring on human health, such as the avoidance of high risk of over dosage or increased therapeutic efficacy. In this work, we demonstrate that the drug doxycycline can act as an Au nanoparticle (doxy-AuNP) growth and capping agent to enhance the response of a surface plasmon resonance (SPR) biosensor for this drug. SPR analysis revealed the high sensitivity of doxy-AuNPs towards the detection of free doxycycline. More specifically, doxy-AuNPs bound with protease-activated receptor-1 (PAR-1) immobilized on the SPR sensing surface yield the response in SPR, which was enhanced following the addition of free doxy (analyte) to the solution of doxy-AuNPs. This biosensor allowed for doxycycline detection at concentrations as low as 7 pM. The study also examined the role of colloidal stability and growth of doxy-AuNPs in relation to the response-enhancement strategy based on doxy-AuNPs. Thus, the doxy-AuNPs-based SPR biosensor is an excellent platform for the detection of doxycycline and demonstrates a new biosensing scheme where the analyte can provide enhancement.

The influence of foliar fertilizer on the biometric indicators and sunflower yield

The results of three-year research on determining the effectiveness of outside the roots extra fertilization of sunflower with complex fertilizers of various application periods under conditions of the Left-Bank Forest-Steppe of Ukraine are given. It was established that a combination of macro – and micro-fertilizers during the growing season of sunflower is appropriate for increasing seeds yield. The most effective measure is the use of three-time extra fertilization with a complex of Sol B (boron 15 %) (0.5 l/ha) and Kod Fol (N14P6K5) v.r. (0.5 l / ha). Keywords: sunflower, microelements, macroelements, extra fertilization, height, leaf surface, yield.

Mechanistic study on –C–O– and –C–C– hydrogenolysis over Cu catalysts: identification of reaction pathways and key intermediates

Sugar alcohols are found to adsorb over Cu catalysts via two vicinal OH-groups, forming a chelate complex with selective –C–O– bond cleavage of adjacent free OH-groups. Different side reactions via unsaturated intermediates on the catalyst surface yield C1 to C5 polyols.

Development of a Novel Rod Compression Technique for Characterizing Local Surface Strength

A nondestructive rod compression has been proposed as a new strength characterizing technique for in-service components. Using electrical discharge machining, milling machining, and stamping, it was possible to machine small rods, typically about 0.5 mm in both diameter and height on the target surface. Static compressions of the rods were carried out using a flat punch and their deformation behaviors were recorded as load-displacement curves. Referring to initial dimension of the rods, engineering stress-strain curves implying the yield strengths were calculated from the deformation curves. Surface yield strengths from the rod compressions were directly compared with reference compression results and their slight discrepancies were discussed from the influences of pre-deformation and damage of the rod and additive compliance of the base.

The Valence Electronic Structure of N-Doped P-Sexiphenyl

ABSTRACTThin films of p-sexiphenyl (6P) were doped with increasing amounts of potassium in situ, and the change in the valence electronic structure of 6P upon the alkali metal deposition was followed with ultraviolet photoelectron spectroscopy. We observe the evolution of new intragap emissions, which are attributed to the formation of bipolarons, even for very low doping concentrations. The low binding energy intra-gap emission exhibits a pronounced asymmetric lineshape, in contrast to the findings when cesium is used as dopant. In order to investigate whether this lineshape is due to different emissive electronic species in the bulk and on the surface of the 6P film the take-off angle for the photoelectrons was varied. As no change in the lineshape is found when going from normal to near-grazing emission we can exclude that charged 6P molecules in the bulk and on the surface yield different valence electronic spectra. Therefore, the characteristic lineshape of the low binding energy emission is proposed to be related to the interaction of the doped organic molecule with the different counterions.