Phospholipid detection by surface-enhanced Raman scattering using silvered porous silicon substrates

Silver particles, predominantly with the size of 40–80 nm, were immersion deposited onto porous silicon to form substrates appropriate for the detection of organic molecules by surface-enhanced Raman scattering technique. These substrates have been demonstrated for the first time to provide detection of phospholipid molecules represented by dipalmitoylphosphatidylcholine at concentrations as low as 10−12 M when a 532 nm laser wavelength is used and 10−11 M at 633 nm wavelength. Label-free detection is realized at these conditions.