Useful disorder for plasmon-enhanced spectroscopic imaging of cell membranes
What is it about?
Large density of gap plasmon hot spots from clusters of nanoparticles produces a high surface-enhanced Raman scattering (SERS) enhancement. A homogeneous and isotropic arrangement of these clusters is driven by block copolymer micelles that self-organize into a near hyperuniform disordered pattern. This helps suppressing the fluctuations of the spot-to-spot SERS response even for confocal detection. The spatially flat SERS response allows reconstructing the label-free chemical map of a challenging cell, the red blood cell. The hemoglobin Raman signature is used as a contrast medium to validate membrane glycoprotein detection on the living cell. Numerical simulations support the experimental data.
Why is it important?
Label-free chemical imaging of live cell membranes represents a hot topic of bio-medical research, potentially providing access to the molecular basis of many significant membrane-related diseases. Herein, we present surface-enhanced Raman scattering (SERS) substrates based on a homogeneous and isotropic random close-packing of silver nanoclusters and characterized by near-hyperuniform disorder. These SERS substrates reveal excellent reproducibility with spatially flat SERS enhancement factor and single molecule sensitivity on centimeter scale. This allows a robust SERS imaging of cell membranes - here demonstrated on erythrocytes - which opens new routes for quantitative surface analysis and dynamic probing of living cells.
The following have contributed to this page: Dr Gianluigi Zito