Confined detection volume of fluorescence correlation spectroscopy by bare fiber probes.
A fiber-tip-based near-field fluorescence correlation spectroscopy (FCS) has been developed for confining the detection volume to sub-diffraction-limited dimensions. This near-field FCS is based on near-field illumination by coupling a scanning near-field optical microscope (SNOM) to a conventional confocal FCS. Single-molecule FCS analysis at 100 nM Rhodamine 6G has been achieved by using bare chemically etched, tapered fiber tips. The detection volume under control of the SNOM system has been reduced over one order of magnitude compared to that of the conventional confocal FCS. Related factors influencing the near-field FCS performance are investigated and discussed in detail. In this proof-of-principle study, the preliminary experimental results suggest that the fiber-tip-based near-field FCS might be a good alternative to realize localized analysis at the single-molecule level.
Lu
Guowei
G
Unité MéDIAN, UFR Pharmacie, Université de Reims Champagne-Ardenne, UMR CNRS 6237, 51 rue Cognacq-Jay, 51096, Reims Cedex, France. guowei.lu@univ-reims.fr
Lei
Franck H
FH
Angiboust
Jean-François
JF
Manfait
Michel
M
D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*