A digitally-addressable, pixelated, DNA fluid-assay, active-matrix micro-structure formed, utilizing low-temperature TFT and Si technology, on a substrate preferably made of glass or plastic, and including at least one pixel which is defined by (a) an addressable pixel site, (b) a sensor home structure disposed within that site for receiving and hosting a functionalized assay site possessing a DNA oligonucleotide probe, and (c) an addressable, pixel-site-specific, energy-field-producing functionalizer (preferably optical) operable to functionalize such a probe on the assay site. Each pixel may also include a pixel-integrated optical detector. Further disclosed are related methodology facets involving (1) the making of such a micro-structure (a) in a precursor form (without a functionalized probe), and thereafter (b) in a finalized/functionalized form (with such a probe), and (2) the ultimate use of a completed micro-structure in the performance of a DNA assay.