Use of Nanostructured Silver Substrates (Coatings) to Study the Content and Conformation of β-carotene

Abstract

Interest in the industrial production of plant and microalgal biomass for biofuels and bioproducts has stimulated studies on microalgal physiology and mechanisms of valuable biomolecules synthesis and accumulation in algal cells. One of the most investigated biomolecules for commercial application are neutral lipids and carotenoids. However, until now the mechanism of the influence of different ambient factors, including application of inductors, on biosynthesis and accumulation of these molecules is not well understood. Partially, the lack of such knowledge is due to restricted technique of investigation. Raman Spectroscopy is one of the advanced methods of cell physiology investigation, which can fill some gaps in our understanding of such processes. The current techniques used in the papers presented show the advantages and other essential specifics of the method applied to plants (most importantly, microalgae) and other species/objects. It was found that the use of a substrate allows to enhance the Raman signal when diluting the sample by 105--106 times, at a substance concentration of 10--9 mol/l. In SERS conditions (i.e., mixing silver colloids to blood sample) hem markers show up, while in normal Raman conditions resonance enhancement allows direct observation of β-carotene features. This highlights the versatility of Raman technique and the prospects for biology and clinical chemistry