Loman, Anastasia

[["dc.bibliographiccitation.firstpage","8236"],["dc.bibliographiccitation.issue","28"],["dc.bibliographiccitation.journal","The Journal of Physical Chemistry B"],["dc.bibliographiccitation.lastpage","8240"],["dc.bibliographiccitation.volume","112"],["dc.contributor.author","Müller, Claus B."],["dc.contributor.author","Loman, Anastasia"],["dc.contributor.author","Richtering, Walter"],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:47:00Z"],["dc.date.available","2018-04-23T11:47:00Z"],["dc.date.issued","2008"],["dc.description.abstract","Fluorescence correlation spectroscopy (FCS) is a powerful technique for measuring diffusion coefficients of small fluorescent molecules at pico- to nanomolar concentrations. Recently, a modified version of FCS, dual-focus FCS (2fFCS), was introduced that significantly improves the reliability and accuracy of FCS measurements and allows for obtaining absolute values of diffusion coefficients without the need of referencing again a known standard. It was shown that 2fFCS gives excellent results for measuring the diffusion of small molecules. However, when measuring colloids or macromolecules, the size of these objects can no longer be neglected with respect to the excitation laser focus. Here, we analyze how 2fFCS data evaluation has to be modified for correctly taking into a count these finite size effects. We exemplify the new method of measuring the absolute size of polymeric particles with simple and complex fluorophore distributions."],["dc.identifier.doi","10.1021/jp802280u"],["dc.identifier.gro","3142165"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13282"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.issn","1520-6106"],["dc.title","Dual-Focus Fluorescence Correlation Spectroscopy of Colloidal Solutions: Influence of Particle Size"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4322"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","4329"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Müller, Claus B."],["dc.contributor.author","Weiß, Kerstin"],["dc.contributor.author","Richtering, Walter"],["dc.contributor.author","Loman, Anastasia"],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:47:02Z"],["dc.date.available","2018-04-23T11:47:02Z"],["dc.date.issued","2008"],["dc.description.abstract","We present a novel calibration technique for determining the shear distance of a Nomarski Differential Interference Contrast prism, which is used in Differential Interference Contrast microscopy as well as for the recently developed dual-focus fluorescence correlation spectroscopy. In both applications, an exact knowledge of the shear distance induced by the Nomarski prism is important for a quantitative data evaluation. In Differential Interference Contrast microscopy, the shear distance determines the spatial resolution of imaging, in dual-focus fluorescence correlation spectroscopy, it represents the extrinsic length scale for determining diffusion coefficients. The presented calibration technique is itself based on a combination of fluorescence correlation spectroscopy and dynamic light scattering. The method is easy to implement and allows for determining the shear distance with nanometer accuracy."],["dc.identifier.doi","10.1364/oe.16.004322"],["dc.identifier.gro","3142169"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13286"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.eissn","1094-4087"],["dc.relation.issn","1094-4087"],["dc.title","Calibrating Differential Interference Contrast Microscopy with dual-focus Fluorescence Correlation Spectroscopy"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","14353"],["dc.bibliographiccitation.issue","19"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","14368"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Dertinger, Thomas"],["dc.contributor.author","Loman, Anastasia"],["dc.contributor.author","Ewers, Benjamin"],["dc.contributor.author","Müller, Claus B."],["dc.contributor.author","Krämer, Benedikt"],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:46:58Z"],["dc.date.available","2018-04-23T11:46:58Z"],["dc.date.issued","2008"],["dc.description.abstract","Fluorescence correlation spectroscopy (FCS) is an important spectroscopic technique which can be used for measuring the diffusion and thus size of fluorescing molecules at pico- to nanomolar concentrations. Recently, we introduced an extension of conventional FCS, which is called dual-focus FCS (2fFCS) and allows absolute diffusion measurements with high precision and repeatability. It was shown experimentally that the method is robust against most optical and sample artefacts which are troubling conventional FCS measurements, and is furthermore able to yield absolute values of diffusion coefficients without referencing against known standards. However, a thorough theoretical treatment of the performance of 2fFCS is still missing. The present paper aims at filling this gap. Here, we have systematically studied the performance of 2fFCS with respect to the most important optical and photophysical factors such as cover slide thickness, refractive index of the sample, laser beam geometry, and optical saturation. We show that 2fFCS has indeed a superior performance when compared with conventional FCS, being mostly insensitive to most potential aberrations when working under optimized conditions."],["dc.identifier.doi","10.1364/oe.16.014353"],["dc.identifier.gro","3142162"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13279"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.eissn","1094-4087"],["dc.relation.issn","1094-4087"],["dc.title","The optics and performance of dual-focus fluorescence correlation spectroscopy"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]