Waveguiding and SERS Simplified Raman Spectroscopy on Biological Samples.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Spectroscopy

Background:

• Ultra-low concentration biomarker detection in biofluids is crucial for early diagnosis and personalized medicine.
• Conventional methods face challenges due to complex sample matrices, non-specific detection, and poor sensitivity.
• Integrating sensors with other devices is difficult, limiting performance and applicability.

Purpose of the Study:

• To develop a new class of optical biosensor for sensitive and label-free detection of biomarkers.
• To overcome spatial constraints in sensor integration for improved applicability.
• To enable continuous monitoring of biological compounds and metabolic pathway variations.

Main Methods:

• Development of an optical biosensor integrating an optical waveguide (OWG) with specific plasmonic surfaces.
• Utilizing surface-enhanced Raman spectroscopy (SERS) for detection.
• Employing a rutile prism for laser coupling to the OWG and a Raman spectrometer for signal collection.
• Fabrication using photolithography and nanofabrication techniques.

Main Results:

• Consistent results in SERS for continuous, label-free detection of biological compounds.
• The OWG successfully guided optical signals to SERS surfaces, overcoming spatial limitations.
• Detection of cell metabolites including Phenylalanine (Phe), Adenosine 5-triphosphate sodium hydrate (ATP), and Sodium Lactate.
• Detection of Human Interleukin 6 (IL6).

Conclusions:

• The developed optical biosensor offers a promising platform for sensitive biomarker detection.
• The integration of OWG and SERS overcomes previous limitations in sensor applicability and performance.
• The biosensor can detect key metabolites and proteins, aiding in the understanding of metabolic pathway variations and disease states.