SERS Substrate-Dependent Interaction of the Anticarcinogenic Drug 5-Fluorouracil with Silver

5-Fluorouracil, an extensively used anticarcinogenic drug, was found to undergo a soft adsorption (i.e., no significant structural changes) on the metal surface of different Ag island films (35, 11, 8.7, and 6.5 nm thick). The 35 nm thick film provided the best SERS signal. The resistance of the Ag-complexed species to washing demonstrates the films' advantage over colloids and makes them very attractive for potential bio-applications.

Both deprotonated forms, which were previously detected on colloidal nanoparticles (50 nm diameter) at neutral pH, are also present in this case. However, the interaction mechanism of 5-FU species appears to be substrate dependent. While on colloidal nanoparticles they are orientated perpendicular or significantly tilted from the surface normal, on the much larger Ag-clusters of the island films (20-200 nm) they lie flat, attached through the carbonyl groups and the π-electrons. The charge-transfer mechanism significantly contributes to the rich information SERS reports for this system.     

The Influence of Competitiveness on SMEs Internationalization Effectiveness. Online Versus Offline Business Networking

ABSTRACT

The article aims to analyze the importance of reinforcing the relational capital of the small- and medium-sized enterprises (SMEs) in the context of a globalized market. It elaborates on the influences of competitiveness on online versus offline business networking with a view to achieve effectiveness in the European steel pipe SMEs internationalization process. The results indicate that internationalization effectiveness is indirectly influenced by competitiveness, with online and offline networking mediating the relationship between the two variables.     

SERS Substrate-Dependent Interaction of the Anticarcinogenic Drug 5-Fluorouracil with Silver

5-Fluorouracil, an extensively used anticarcinogenic drug, was found to undergo a soft adsorption (i.e., no significant structural changes) on the metal surface of different Ag island films (35, 11, 8.7, and 6.5 nm thick). The 35 nm thick film provided the best SERS signal. The resistance of the Ag-complexed species to washing demonstrates the films' advantage over colloids and makes them very attractive for potential bio-applications.

Both deprotonated forms, which were previously detected on colloidal nanoparticles (50 nm diameter) at neutral pH, are also present in this case. However, the interaction mechanism of 5-FU species appears to be substrate dependent. While on colloidal nanoparticles they are orientated perpendicular or significantly tilted from the surface normal, on the much larger Ag-clusters of the island films (20–200 nm) they lie flat, attached through the carbonyl groups and the π-electrons. The charge-transfer mechanism significantly contributes to the rich information SERS reports for this system.