Time filter

Source Type

Peksa V.,Charles University | Jahn M.,Friedrich - Schiller University of Jena | Jahn M.,Leibniz Institute of Photonics Technology IPHT | Stolcova L.,Czech Technical University | And 9 more authors.
Analytical Chemistry | Year: 2015

Considering both the potential effects on human health and the need for knowledge of food composition, quantitative detection of synthetic dyes in foodstuffs and beverages is an important issue. For the first time, we report a fast quantitative analysis of the food and drink colorant azorubine (E 122) in different types of beverages using surface-enhanced Raman scattering (SERS) without any sample preparation. Seven commercially available sweet drinks (including two negative controls) with high levels of complexity (sugar/artificial sweetener, ethanol content, etc.) were tested. Highly uniform Au "film over nanospheres" (FON) substrates together with use of Raman signal from silicon support as internal intensity standard enabled us to quantitatively determine the concentration of azorubine in each drink. SERS spectral analysis provided sufficient sensitivity (0.5-500 mg L-1) and determined azorubine concentration closely correlated with those obtained by a standard HPLC technique. The analysis was direct without the need for any pretreatment of the drinks or Au surface. Our SERS approach is a simple and rapid (35 min) prescan method, which can be easily implemented for a field application and for preliminary testing of food samples. © 2015 American Chemical Society.

Jahn M.,Friedrich - Schiller University of Jena | Jahn M.,Leibniz Institute of Photonics Technology IPHT | Patze S.,Friedrich - Schiller University of Jena | Patze S.,Leibniz Institute of Photonics Technology IPHT | And 19 more authors.
Analyst | Year: 2016

A comprehensive review of theoretical approaches to simulate plasmonic-active metallic nano-arrangements is given. Further, various fabrication methods based on bottom-up, self-organization and top-down techniques are introduced. Here, analytical approaches are discussed to investigate the optical properties of isotropic and non-magnetic spherical or spheroidal particles. Furthermore, numerical methods are introduced to research complex shaped structures. A huge variety of fabrication methods are reviewed, e.g. bottom-up preparation strategies for plasmonic nanostructures to generate metal colloids and core-shell particles as well as complex-shaped structures, self-organization as well as template-based methods and finally, top-down processes, e.g. electron beam lithography and its variants as well as nanoimprinting. The review article is aimed at beginners in the field of surface enhanced spectroscopy (SES) techniques and readers who have a general interest in theoretical modelling of plasmonic substrates for SES applications as well as in the fabrication of the desired structures based on methods of the current state of the art. © The Royal Society of Chemistry 2016.

Loading Leibniz Institute of Photonics Technology IPHT collaborators
Loading Leibniz Institute of Photonics Technology IPHT collaborators