Reflection-enhanced LIF for improved label-free classification of blood inflammation with complementary LIBS...

Area of Science:

• Biophotonics
• Spectroscopy
• Medical Diagnostics

Background:

• Conventional laser-induced fluorescence (LIF) faces limitations in sensitivity and the prozone effect for immunoassay applications.
• Accurate classification of inflammation severity is crucial for effective patient management.

Purpose of the Study:

• Introduce and evaluate a reflection-enhanced laser-induced fluorescence (RELIF) technique for label-free classification of inflammation severity in blood serum.
• Compare RELIF performance against conventional LIF and assess its ability to overcome existing limitations.

Main Methods:

• Developed a RELIF technique utilizing a cuvette with a reflective surface to amplify fluorescence signals.
• Performed complementary laser-induced breakdown spectroscopy (LIBS) on dried serum samples for elemental analysis.
• Employed multivariate analysis, including PLSR and PLS-DA, and ROC curves for model performance assessment.

Main Results:

• RELIF achieved 1.30× to 1.53× higher fluorescence signals compared to conventional LIF.
• RELIF successfully distinguished all three inflammation severity classes, outperforming LIF, which struggled with severe inflammation samples.
• The RELIF-based model demonstrated superior classification performance with an AUC of 0.94 versus 0.84 for LIF.
• LIBS analysis supported class separation via Ca and CN emission differences.

Conclusions:

• The RELIF technique offers enhanced spectral resolution and sensitivity for label-free inflammation classification.
• RELIF effectively overcomes the prozone effect and low sensitivity issues of conventional LIF.
• The combined RELIF-LIBS strategy provides a rapid, cost-effective, and non-destructive tool for diagnosing inflammation severity.