Bifurcated Fiber Optic Bundle   ••••

The bifurcated fiber bundle is utilized for in-situ fluorescence measurements. The fiber bundle assembly is made of two separate bundles: one connected to the excitation channel of the spectrofluorometer and the second connected to the emission channel. The two bundles are joined in the common leg utilized to acquire the measurements on the sample. The excitation and collection fibers are arranged in the common leg using one of two different patterns. In one pattern, the excitation fibers are located in the middle of the common leg and the collection fibers are located on an outer ring. In a second pattern, the fibers are interdispersed. The selection of each pattern is dictated by the type of experiment. The fluorescence is carried back to the emission monochromator of the fluorometer or to a polychromator coupled to the diode array. A spectrum of a remote sample can be recorded; similarly, the decay times of fluorescence can be measured. The bifurcated fiber is mounted onto a sample holder for easy placement into the sample compartment of the instrument. The accessory includes the focusing lenses in the excitation and emission channels.

Single Fiber Optic Bundle   ••••

Chemically Activated Fiber Tip and Fiber Optics, Complete with XY Control and Dichroic Mirror   ••••

Analyte-sensitive fluorescence probes are coated onto the tip of a fiber. The excitation light, coming from the excitation monochromator or coming from a laser, passes the dichroic filter at the entrance of the fiber and is focused into the fiber. The excitation light travels down the fiber and excites the fluorescent probes located on the tip. The fluorescence emitted by the probes travels back through the fiber. The dichroic mirror separates the fluorescence from the excitation light, and the fluorescence is diverted to the detectors. When the fiber is immersed in a solution, the fluorescence properties of the probes (intensity, lifetime) change and such changes are detected by the spectrofluorometer. For instance, the intensity of fluorescein may change due to pH changes of the solution. The fiber is made out of silica to minimize any background fluorescence. The accessory is mounted on a baseplate for easy insertion into the spectrofluorometer.