Bk7 glass substrates

Cholera toxin (CT) from Vibrio cholera, Triton X-100, 1-octadecanethiol (98%), and n-octadecyltrichlorosilane (OTS, 90+%) were from Sigma-Aldrich (St. Louis, MO). Trehalose was from Swanson Health Products (Fargo, ND).
1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-|6-[(7-nitro-2−1,3-benzoxadiazol-4-yl)amino]hexanoyl}-sn-glycero-3-phosphocholine (NBD-PC) were from Avanti Polar Lipids (Alabaster, AL). Monosialoganglioside GM1 (NH₄⁺ salt) and monosialoganglioside GM2 (NH₄⁺ salt) were from Matreya (Pleasant Gap, PA). Monosialoganglioside GM3 was from EMD Biosciences (La Jolla, CA). BK-7 glass substrates were from Corning (Painted Post, NY). Chromium and gold used for electron-beam evaporation were acquired as pellets of 99.99% purity from Kurt J. Lesker (Jefferson Hills, PA).

β-Casein, trypsin (from bovine pancreas), anisole, poly(methyl methacrylate) (PMMA, MW ~ 996 kDa), poly(allylamine hydrochloride) (PAH, MW ~ 56 kDa), titanium(IV)bis(ammo-niumlactato)dihydroxide solution (TALH, 50 wt% in H₂O), trifluoroacetic acid (TFA, 99%), Super-DHB, and n-octadecyltri-chlorosilane (C18, 90%) were from Sigma-Aldrich (St. Louis, MO). Ethanol (200 proof) and acetonitrile (ACN) were from Fisher Scientific (Pittsburgh, OH). Phosphoric acid (85% w/w) was from EMD Millipore (Billerica, MA). Poly(-diallyldimethylammonium chloride) solution (PDDA, 20%) and carboxylated polystyrene nanospheres (0.2 μm, 2.6% solids) were from Polysciences, Inc. (Warrington, PA). BK7 glass substrates were from Corning (Painted Post, NY). Chromium and gold used for electron-beam evaporation were acquired as pellets of 99.99% purity from Kurt J. Lesker (Jefferson Hills, PA). Nanopure water (≥18 MΩ cm), purified through a Barnstead E Pure filtration system (Thermo Scientific, Rockford, IL), was used for all reagent preparations.