Silicon wafers (100 orientation, P/B doped, resistivity 1–10 Ω-cm, thickness 475–575 μm) were purchased from International Wafer Service. Silane coupling agents, 3-aminopropyltriethoxysilane (APTES, 99.7%), 3-aminopropyltrimethoxysilane (APTMS, 98.5%), N-(6-aminohexyl)aminomethyltriethoxysilane (AHAMTES, 99.7%), N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPTES, 97.4%), and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS, 98.3%), were purchased from Gelest. The purity information was provided by the manufacturer. The silanes were stored in Schlenk flasks under nitrogen and used without further distillation. House-purified water (reverse osmosis) was purified in a Millipore Milli-Q Biocell System (Millipore) that involved reverse osmosis, ion exchange, and filtration (18.2 MΩ-cm). Other reagents were used as received from Fisher Scientific. Solution-phase silanization was carried out in anhydrous toluene that was dried and deoxygenated using a Pure Solv 400-6 solvent purification system (Innovative Technology). All glassware was cleaned in a base bath (potassium hydroxide in isopropyl alcohol and water), rinsed with distilled water (3×), and stored in a clean oven at 110 °C until use.