SERS based metrology at a primary level

Proposal, April 2006

Surface-Enhanced Raman Scattering (SERS) can be used as highly sensitive and even potentially primary ratio method for amount of substance measurements or single molecule detection. The SERS effect provides substantial Raman signal enhancement and occurs when molecules adsorb to metal surfaces with roughness in the order of nanometers. The use as a primary method relies on the application of isotope dilution techniques. This allows determining isotopomer (abundance ratios from relative intensities of characteristic Raman bands that were shifted with respect to each other due to a mass-dependent isotope effect. (Isotopomers: isotopic isomers, isomers having the same number of isotopic atoms but differing in their position)

The aim of this project is to demonstrate and extend the measurement capabilities of SERS based analyses with respect to the determination of low concentrated biomolecules in complex matrices.

The key objectives are:

to develop and standardize methods for preparation and characterization of reproducible and highly active SERS substrates. (Target date: 1/1/07)
to understand and control the analyte-substrate interaction at a molecular level for high SERS enhancement factors and reproducible results using isotope dilution strategies for simple target molecules. (Target date: 1/7/07)
to evaluate the techniques for analyzing higher mass molecular compounds such as proteins (Target date: 1/6/08)

Subjects
Metrology in Chemistry (MC)
Coordinating Institute
PTB (Germany)
Participating Partners
NPL (United Kingdom)