Accurate correction method and algorithm of fluorescence secondary inner filter effect (sIEF) in fluorescence...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Photochemistry

Background:

• Fluorescence spectroscopy is a key analytical technique.
• The secondary inner filter effect (sIFE) causes significant errors, including spectral distortion and loss of linearity.
• Existing methods struggle to fully correct for sIFE-induced errors.

Purpose of the Study:

• To introduce a novel parameter, the fluorescence attenuation absorption index (n_opt), for quantifying sIFE.
• To develop and validate an algorithm for fluorescence spectroscopic correction using n_opt.
• To assess the impact of solute-solvent systems on sIFE correction.

Main Methods:

• Proposed a new parameter, n_opt, independent of geometric factors and concentration.
• Developed a correction algorithm based on n_opt.
• Experimentally validated the method using fluorescein sodium, rhodamine B, rhodamine 6G, and chlorophyll-a solutions across various concentrations.

Main Results:

• n_opt accurately reflects sIFE impact and corrects for beam shape non-idealities.
• The algorithm successfully corrected intensity attenuation and peak red-shift caused by sIFE.
• The linear range of fluorescence intensity versus concentration was expanded, reducing prediction errors.

Conclusions:

• The proposed n_opt parameter and correction algorithm effectively mitigate sIFE in fluorescence spectroscopy.
• The method enhances measurement accuracy and reliability across different fluorescent substances and solvents.
• This advancement broadens the applicability of fluorescence spectroscopy in quantitative analysis.