Based on the assumption that the methyl groups provide a steric barrier for N-Au binding, we propose that accelerated growth on Au(111) limits the time TEMPO spends in the plasma environment, therefore reducing molecular damage and increasing NO retention. As the film forms, the surface sticking coefficient will reduce, resulting in similar growth rates across all samples. This appears to be confirmed by XPS spectra measured on thicker TEMPO films deposited at 300 s and 600 s, which show similar structure in the N 1s region where peaks are found to converge to a single energy of 399.2 eV, identical to that of the 5 second TEMPO film on SiO2 and HOPG. Overview spectra for each sample discussed here can be found in Figure . We note that control experiments, where the plasma was not ignited, result in virtually no deposition (Figure ), highlighting the necessity of the plasma environment. We also note that XPS could not be collected on the TEMPO molecular powder, which is not stable under ultra-high vacuum environments, and sublimates even at room temperature. To briefly summarise these results, we find that plasma polymer growth of TEMPO films strongly depend on the surface material in the first 30 nm of growth. XPS reveals that the TEMPO chemistry is most affected in the first layer of growth, beyond which molecules exhibit a consistent chemical structure. AFM measurements, however, indicate significant variation in topography up to 30 nm thickness. Beyond 30 nm thickness, the coatings studied become 'surface agnostic', converging to a flat, uniform layer of comparable roughness.