Raman sensitivity enhancement for aqueous absorbing sample using Teflon-AF 2400 liquid core optical fibre cell.

The compatibility Teflon-AF 2400 liquid core optical fibre with resonance Raman spectroscopy (RRS-LCOF) was used to detect aqueous biomolecules. The maximum sensitivity enhancement factor for concentrations greater than the detection limit in a conventional cell was 10, and detection limit reduction of about 1000-fold have been achieved for the measurement of aqueous absorbing sample using Teflon-AF 2400 fibre Raman cell compared to the conventional cell. We were able to collect spectra of 2.5 x 10(-9) and 2.5 x 10(-10) M aqueous beta-carotene using 16.2 mW of laser power and 10s integration time. This volume of a 2.5 x 10(-10) M aqueous solution corresponds to only 1.5 fmol or 830 fg of beta-carotene. The results of this preliminary study indicate that RRS-LCOF has potential in bioanalytical and biomedical applications.