SERS As A Single

Molecule Biophysical Tool

Since the first demonstration of single molecule surface enhanced Raman spectroscopy (SERS) of hemoglobin over 15 years ago, little work has been carried out toward realizing the potential of SERS as a single molecule biophysical technique.  We believe this is because existing SERS substrates cause protein denaturation and inactivity.  Thus, currently our efforts are towards the development of novel SERS substrates in which single protein molecules can be reproducibly incorporated in a non-denaturing manner.  We are currently taking single particle LSPR/SERS measurements of novel liposome-based plasmonic substrates.​

Biosensing utilizing Localized Surface Plasmon Resonance (LSPR) offers relatively inexpensive, label-​free, facile detection that is amenable to on-chip devices.  In LSPR biosensing, biomolecular binding to gold and silver nanoparticles produces a change in the nanoparticle environment, which often yields a change in color.  These minaturized, ultrasensitive, colorimetric devices provide great opportunity for biosensing in resource-limited environments.  However, several challenges remain, such as:


● Measuring binding of small molecules is problematic

● Lack of specificity and biofouling, particularly in biological fluids

● Binding events with membrane-associated proteins are problematic

● Little has been done towards multiplexing and microfluidic LSPR applications


Projects are currently ongoing in the Sagle group aimed at improving these four problematic areas.

LSPR Biosensing