Laser Modification and Functionalization of Substrates

A method of functionalizing a surface comprising:

• (a) providing a substrate;
• (b) directing light onto the substrate wherein the light melts material of the substrate without causing measurable loss of material therefrom other than material of any background layer of the substrate, thereby creating a primarily-functionalized region;
• and
• (c) exposing the primarily-functionalized region to a first chemical environment which causes the primarily-functionalized region to undergo a secondary change in functionality resulting in a secondarily-functionalized region.

A system for making an assay device comprising:

• (a) a laser capable of delivering a pulse of laser light having an energy between about between about 109 and 1010 J/cm;
• (b) a microlens array in optical communication with said laser;
• (c) a substrate comprising a hydrophobic background layer, and an underlying layer, said substrate being positioned with respect to said microlens array and said laser such that light from said laser focused through said microlens array falls on multiple spatially-separated regions of said substrate;
• (d) means for timing a single pulse of light from said laser in operative communication with said laser, whereby said single pulse of light delivers sufficient energy to melt portions of said underlying layer in the regions where said light falls without causing loss of material from said underlying layer, while removing portions of said background layer in the regions where said light falls.

An assay device comprising a substrate comprising:

• (a) an underlying layer not comprising relief features other than ripples resulting from localized melting;
• and comprising multiple, spatially-separated functionalized regions thereon;
• and
• (b) a background hydrophobic layer coating said underlying layer between said functionalized regions.