Sample interview questions: Can you explain the concept of plasmonic biosensing and its potential applications?
Sample answer:
Plasmonic biosensing is an innovative technique that harnesses the extraordinary properties of plasmons, coherent oscillations of free electrons in metal nanoparticles, to achieve highly sensitive and label-free detection of biomolecules. By manipulating these plasmonic properties, it enables real-time monitoring of biomolecular interactions with remarkable sensitivity, specificity, and minimal sample preparation.
The underlying principle of plasmonic biosensing relies on the interaction of light with metal nanoparticles, typically gold or silver, resulting in localized surface plasmon resonance (LSPR). When light strikes these nanoparticles, it excites surface plasmons, causing the nanoparticles to oscillate collectively. These oscillations generate strong electric fields that extend beyond the nanoparticle surface, creating an evanescent field that is highly sensitive to changes in the surrounding environment, including the presence of biomolecules.
The unique optical properties of plasmonic nanoparticles enable label-free detection of biomolecules. By monitoring the changes in LSPR, such as shifts in resonance wavelength, intensity, or linewidth, one can infer the presence and concentration of specific biomolecules in the vicinity of the nanoparticles. This allows for real-time and continuous monitoring of biomolecular interactions, such as binding events, conformational changes, and molecular recognition processes.
Plasmonic biosensors offer several advantages over conventional biosensing methods. They are label-free, eliminating the need for labeling biomolecules with fluorescent tags or radioactive isotopes, which can interfere with their natural behavior and introduce additional complexity. Plasmonic biosensors also provide high sensitivity, enabling the detection of minute amounts of biomolecules, down to single-molecule levels in certain cases. Additionally, they offer… Read full answer