A novel turbidity compensation method for fluorescence spectroscopy and application in the detection of two algae...

Turbidity interference in measurements can reduce the accuracy of fluorescence detection. Conventional turbidity compensation methods directly establish the relationship between turbidity value and fluorescence but cannot accurately characterize the complex interference of turbidity on fluorescence detection. This paper introduces a novel turbidity compensation technique that separates the interference caused by turbidity particles into scattering intensifying and scattering-absorption attenuating components and corrects them separately. First, the scattering spectrum overlapping with fluorescence is estimated and subtracted from the actual sample spectrum to mitigate the fluorescence intensification caused by scattering. Then, attenuation coefficients at different turbidity intervals are calculated to compensate for fluorescence attenuation. Finally, the two components are combined to obtain the final corrected result. Based on the proposed method, the fluorescence spectra data of Platymonas helgolandica var. tsingtaoensis and Synechococcus elongatus undeod is evaluated. The core problem for comper different turbidity interferences were analyzed. Intensifying and attenuating coefficients based on turbidity values and scattering spectra were determined, ensuring adaptability to known and unknown turbidity conditions. The study results show that the fluorescence variation at different concentrations and turbidity levels are influenced by sample concentration and turbidity, exhibiting nonlinear behavior. The compensation model developed was applied to experimental data, achieving a mean relative error of less than 4% and a satisfactory root-mean-square error, significantly enhancing prediction accuracy. This method offers a straightforward and rapid application to detect a wide range of fluorescent substances.