Selective TERS detection and imaging through controlled plasmonics.

Area of Science:

• Chemical Imaging
• Spectroscopy
• Biophysics

Background:

• Enhanced Raman spectroscopy techniques, including Tip-Enhanced Raman Spectroscopy (TERS), enable sensitive molecular detection in complex environments.
• Plasmonic interactions between a TERS tip and a metal surface are known to significantly enhance Raman signals.
• Selective imaging of specific molecules, particularly proteins, remains a challenge in complex biological systems.

Purpose of the Study:

• To develop a method for selectively imaging proteins on surfaces and within cell membranes using SERS.
• To utilize SERS spectra of purified proteins to create models for identifying specific protein receptors.
• To demonstrate the capability of controlled plasmonic interactions for achieving selectivity in TERS imaging.

Main Methods:

• Acquisition of SERS spectra from purified proteins.
• Development of a multivariate regression model based on protein SERS responses.
• Application of the regression model to filter TERS spectra for selective protein receptor imaging.
• Analysis of mutant proteins to identify key amino acid contributions to the TERS signal.

Main Results:

• SERS spectra from purified proteins were successfully used to create a predictive model.
• The regression model enabled selective imaging of protein receptors on nanoparticles and cell membranes.
• Mutant protein experiments revealed significant contributions of specific amino acids to the TERS signal, allowing receptor differentiation.
• Controlled plasmonic interactions led to highly selective TERS imaging.

Conclusions:

• This SERS-based approach provides high selectivity for imaging specific protein receptors.
• The method allows for the differentiation of protein receptors based on their unique spectral fingerprints.
• This technique holds significant potential for identifying membrane receptors involved in drug targeting and chemical signaling pathways.