Figure 3. Influence of Laser Fluence and Iterations on Pattern Size.

10 nm Au films were functionalized with an OEG-terminated alkanethiol and arrays of 1×20 pixel ROIs of the SAM were thermally desorbed with a 532 nm laser focused through a 20× (NA0.8) objective with varying laser fluence (12.8–50.8 nJ μm⁻²) and number of iterations (125–10,000) per ROI. The patterned surfaces were exposed to HFN, the HFN fluorescently labeled, the surfaces imaged (see Fig 1B for a representative image), the patterns mathematically fit with ellipses, and the (A,B) minor axis and (C,D) area measured for each set of patterning conditions. The (A) minor axis and (C) area displayed a linear increase with increased laser fluence at a constant number of iterations (1,000) per ROI. The (B) minor axis and (D) pattern area increased with increased iterations at a constant fluence (50.8 nJ μm⁻²) that plateaued at ~5,000 iterations.