The preparation of aldehyde-terminated substrates from 2-(10-undecen-1-yl)-1,3-dioxolane is outlined in Scheme 1 . Amorphous carbon thin films (15 nm) were deposited onto commercially prepared gold-coated glass slides by DC magnetron sputtering a graphite source at a base pressure of 2 × 10−6 Torr and an Ar pressure of 3 mTorr (Denton Vacuum, Moorestown, NJ). The amorphous carbon film thicknesses were measured with a calibrated quartz crystal microbalance, located in the sputtering instrument. The gold-coated slides contained 100 nm thick gold film with a 5 nm chromium under layer to provide better adhesion to the glass substrate (Evaporated Metal Films Co, Ithaca, NY). Prior to use, the gold-coated slides were rinsed with deionized (DI) water and dried under a stream of nitrogen gas.
The amorphous carbon substrates were photochemically functionalized using a modified procedure for the functionalization of diamond thin film substrates, developed in our laboratory.9 First, each amorphous carbon thin film was hydrogen-terminated in a 13.56 MHz inductively coupled hydrogen plasma for 12 min (30 Torr H2, room temperature). Next, 30 µL of the 2-(10-undecen-1-yl)-1,3-dioxolane molecule (neat) was placed directly onto the newly hydrogen-terminated surface and covered with a quartz coverslip. The substrates were then irradiated with a low-pressure mercury lamp (λmax = 254 nm, 0.35 mW/cm2), under nitrogen purge. After the photoreaction the substrates were rinsed with ethanol and DI water, dried under a stream of nitrogen gas, and stored in a desiccator until needed.
The functionalized substrates were deprotected in a 60 °C, 1.5 M HCl solution to yield the aldehyde-terminated, amorphous carbon surface.
The amorphous carbon substrates were photochemically functionalized using a modified procedure for the functionalization of diamond thin film substrates, developed in our laboratory.9 First, each amorphous carbon thin film was hydrogen-terminated in a 13.56 MHz inductively coupled hydrogen plasma for 12 min (30 Torr H2, room temperature). Next, 30 µL of the 2-(10-undecen-1-yl)-1,3-dioxolane molecule (neat) was placed directly onto the newly hydrogen-terminated surface and covered with a quartz coverslip. The substrates were then irradiated with a low-pressure mercury lamp (λmax = 254 nm, 0.35 mW/cm2), under nitrogen purge. After the photoreaction the substrates were rinsed with ethanol and DI water, dried under a stream of nitrogen gas, and stored in a desiccator until needed.
The functionalized substrates were deprotected in a 60 °C, 1.5 M HCl solution to yield the aldehyde-terminated, amorphous carbon surface.
