Label-free surface plasmon polariton application for labelled biomolecule detection

Area of Science:

• Biophysics
• Optical Sensing
• Biochemistry

Background:

• Label-free biosensing offers advantages over traditional methods.
• Surface Plasmon Polaritons (SPP) enable sensitive detection of molecular interactions.
• Bovine Serum Albumin (BSA) is a common model protein in biological studies.

Purpose of the Study:

• To experimentally apply a label-free SPP method for detecting CF®680 dye-labeled BSA.
• To analyze the optical properties and adsorption behavior of the BSA-CF680 complex on an SPP sensing surface.
• To investigate the potential for spectral analysis in biomolecule detection.

Main Methods:

• Utilized Surface Plasmon Polaritons (SPP) for label-free detection.
• Employed total internal reflection ellipsometry to analyze optical properties.
• Used fluorescence microscopy to study absorption and fluorescence characteristics of BSA-CF680.
• Investigated biomolecule adsorption on the SPP sensing surface.

Main Results:

• Observed an increased SPP quality factor with labeled BSA-CF680 compared to unlabeled BSA, indicating SPP-biomolecule coupling.
• Demonstrated that higher emitter counts or lower mode volumes are needed for strong coupling.
• Characterized the optical properties and adsorption of the BSA-CF680 complex.

Conclusions:

• The combined label-free SPP and labeled biomolecule approach shows promise for biomolecule detection.
• Spectral analysis offers an alternative detection strategy.
• Further optimization is needed to achieve strong coupling for enhanced sensitivity.