Application Note #150
SAM thicknesses: vinylphosphonic (VPA), octylphosphonic (OPA), and tetradecylphosphonic acid (TPA).
Phosphonic acids adsorption behavior was studied using Multi-Parametric Surface Plasmon Resonance (MP-SPR). Tetradecylphosphonic acid (TPA) adsorption onto differently treated gold surfaces was measured. Piranha and ammonia/hydrogenperoxide treatments were found to be the most optimal for the SAM formation. TPA, vinylphosphonic acid (VPA), and octylphosphonic acid (OPA) adsorption onto the piranha treated surface was studied, and the thickness and the refractive index of the deposited layers were determined. The SAMs were 0.68 nm (VPA), 1.41 nm (OPA) and 1.73 nm (TPA) thick, and thicknesses were in good agreement with the expected molecular length.
- If you are interested in reading more, see AN#128 about thickness and refractive index of polyelectrolytes and AN#149 about polymer characterization using MP-SPR.
- Do you want to find out how to calculate thickness out of MP-SPR measurements? Click here
- Do you want to see how MP-SPR instruments work? Click here
- Do you want to see MP-SPR instruments comparison? Click here
- Have a look at original publication here: Niegelhell et al. (2016).