Abstract: FR-PO0058
AKI/CKD Diagnosis Through Optoelectronic-Based Urine Analysis
Session Information
- AKI: Epidemiology, Risk Factors, and Prevention
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 101 AKI: Epidemiology, Risk Factors, and Prevention
Authors
- Moreno, Ana Filipa, Instituto Politecnico de Lisboa Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal
- Fantoni, Alessandro, Instituto Politecnico de Lisboa Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal
- da Fonseca, Francisca Gaudêncio, Centro Hospitalar de Setubal EPE, Setúbal Municipality, Setubal, Portugal
- Soto, Karina, Centro Hospitalar de Setubal EPE, Setúbal Municipality, Setubal, Portugal
Background
Acute Kidney Injury (AKI) is characterized by a sudden and often reversible loss of kidney function, increasing the risk of mortality and progression to chronic kidney disease (CKD). Current diagnostic approaches based on serum creatinine are inadequate for early detection. This study explores the potential of non-invasive optoelectronic techniques (fluorescence and Raman spectroscopy) for identifying urinary biomarkers associated with AKI and CKD.
Methods
Urine samples were collected from anonymous volunteers and patients in the Nephrology Unit. The study included samples from healthy individuals (n=7), CKD patients (n=6), and AKI patients (n=2). Standard creatinine solutions (1.25–100 mg/dL) were also prepared as spectral references.
Fluorescence measurements were performed using a Jasco FP-8300 spectrofluorometer and 1 cm path length quartz cuvettes. Three-dimensional fluorescence spectra were acquired by varying excitation and emission wavelengths at room temperature. Raman spectra were obtained using a 532 nm laser-equipped spectrometer. Data analysis focused on identifying distinct spectral features associated with pathological conditions.
Results
Fluorescence spectroscopy effectively differentiated creatinine concentrations and revealed distinct spectral signatures between healthy and pathological samples. Urine from AKI and CKD patients exhibited increased fluorescence in emission regions corresponding to aromatic amino acids and protein metabolites (notably tryptophan), indicating biomarker accumulation.
Conversely, Raman spectroscopy demonstrated limited sensitivity to creatinine due to background noise and the poor scattering efficiency of polar molecules. Nevertheless, spectra from some CKD samples showed peaks potentially attributable to calcium oxalate. Increasing laser power from 5 mW to 80 mW significantly improved signal intensity, signal-to-noise ratio, and spectral clarity, revealing consistent patterns in this wavenumber range across different sample groups.
Conclusion
Fluorescence spectroscopy shows strong potential as a non-invasive technique for early AKI detection. While Raman spectroscopy currently faces technical limitations, its utility could be enhanced with further optimization. Together, these optoelectronic methods present a promising dual-modality approach to nephrological diagnostics.