PDMS stamps were inked with C 16 SH by rubbing the surfaces of stamps with a cotton swab pre-soaked with a solution of 20 mM [27] C 16 SH in ethanol followed by drying in a stream of nitrogen. The patterned SAMs were formed by pressing the inked stamps in contact with the gold substrates for about 1 min. The substrate was then washed with ethanol and DI water and blown dry in N 2 stream.Underpotential Deposition: The procedure for underpotentially depositing silver and copper has been described previously [8]. For the upd of copper onto gold, the working electrode was cycled at a rate of 10 mV s ±1 from 0 to 450 mV and emersed from the electrochemical cell under a controlled potential on the third anodic scan at 135 mV (vs. Cu wire) for u Cu = 0.6. For the upd of silver, the working electrode was cycled at 10 mV s ±1 from 0 to 650 mV and emersed under a controlled potential on the third cathodic scan at 60 mV (vs. Ag wire) for u Ag = 0.9. After emersion, the substrates were rinsed with absolute ethanol and blown dry in a N 2 stream. The coverages of the upd adlayers were determined by XPS as described previously [24].Desorption of SAMs: The SAM-patterned electrodes were cycled at 50 mV s ±1 from 0.05 V to ±1.4 V (vs. Ag/AgCl) in 0.5 M KOH in ethanol to reductively desorb the SAMs from the substrates [17]. During the final scan, the potential was held at ±1.4 V and the substrate was removed from the electrochemical cell under controlled potential. The sample was rinsed with absolute ethanol and blown dry in a N 2 stream.Formation of PM Patterns: Dilute solutions of diazomethane in ether were carefully prepared according to a literature procedure [28]. Warning: diazomethane is highly explosive and highly toxic and should be handled with extreme care. The concentration of diazomethane in ether was determined by titration with benzoic acid. Substrates were placed in an ethereal solution containing a desired concentration of DM for a predetermined period of time at 0 C. The amount of time the samples were exposed to air after emersion from the electrochemical cell and prior to DM exposure was~1±2 min.Characterization: AFM images of PM films were obtained with a Nanoscope III scanning probe microscope (SPM) equipped with a J piezoelectric scanner (Digital Instruments, Santa Barbara, CA). An area of 120 120 lm 2 was scanned in tapping mode to attain the height images under an ambient laboratory environment. The images were plane fitted and filtered to remove noise using the instrument software.

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