Blu-Ray Discs as Universal Biochip Substrates: Lithography-Free Surface Activation and Assay Patterning.

Blu-ray discs (BDs) are advantageous in comparison with other optical discs (compact discs and digital versatile discs) in terms of not only their storage capacity but also the high-quality materials fabricated from. We have recently discovered that the "Hard Coat" film of Verbatim BDs is in fact a unique type of polymeric substrates that can be readily activated and adapted for biochip fabrications. Particularly, the Hard Coat film peeled from BDs is optically transparent without any fluorescence background, which can be activated by treating with a common base (1.0 M NaOH) at a slightly elevated temperature (55 °C). The surface density of reactive carboxylic acid groups generated, 6.6 ± 0.7 × 10-9 mol/cm2, is much higher than that on polycarbonate upon UV/ozone irradiation (4.8 ± 0.2 × 10-10 mol/cm2). There are no significant physical damages to the substrate morphology, and the aging effect is minimal. More importantly, the BD substrate can be patterned using either cut-out filter paper masks or microfluidic channel plates; both are lithography-free, bench-top methods that facilitate the device fabrication in a common laboratory setting. With classical biotin-streptavidin binding and DNA hybridization arrays as trial systems, we have also demonstrated this new type of biochip substrates for quantitative assay applications.