Plasmonic Nanosensors and Nanoprobes: Monitoring Health from the Gene Level, Single Cell Systems to Medical Diagnostics
Tuan Vo-Dinh (Duke University)
This lecture provides an overview of recent developments in our laboratory for several plasmonic nanomaterials and biosensing technologies that allow biomedical diagnostics from the gene level to single-cell, and whole body systems.
The first technology involves interactions of laser radiation with metallic nanoparticles, inducing very strong enhancement of the electromagnetic field on the surface of the nanoparticles.
These processes, often called "plasmonic enhancements", produce the surface-enhanced Raman scattering (SERS) effect that could enhance the Raman signal of molecules on these nanoparticles more than a million fold.
The SERS technology can be used to directly detect chemical species and biological species with exquisite sensitivity in environmental and biomedical samples.
A SERS-based nanoprobe technology, referred to as "Molecular Sentine"" nanoprobes, has been developed to detect DNA targets of pathogenic agents (e.g., HIV) and biomarkers of diseases (e.g., BRCA1, ERB2 breast cancer genes).
Using nanofabrication, SERS-based plasmonic nanochip systems can also be developed for use as environmental sensors and diagnostic systems for point-of-care and global health applications.
In the field of biosensing of individual cells a unique advance has been the development of optical nanosensors, which have dimensions on the nanometer (nm) size scale.
Using lasers as excitation sources for these nanosensors, it has become possible to probe physiological parameters (pH), individual biochemical species (DNA adducts) and monitor molecular pathways (apoptosis) in a single living cell.
These nanosensors lead to a new generation of nanophotonic tools that can detect the earliest signs of disease at the single-cell level and have the potential to drastically change our fundamental understanding of the life process itself.
Spectrochemical detection using plasmonic nanomaterials and biosensing technologies are definitely bringing a bright future to biochemical and medical research and could ultimately lead to the development of new modalities of environmental sensing, early diagnostics, drug discovery, and medical treatment beyond the cellular level to that of individual organelles and even DNA, the building block of life.