Improved Biomolecule microarrays by Printing on Nanoporous Aluminum Oxide Using a Continuous‐Flow Microspotter

Abstract Biomolecules, including protein A, albumin, and immunoglobulin G, are spotted on top of a nanoporous substrate by using a continuous‐flow microspotter (CFM) system, which normally produces spots 3 to 4 orders of magnitude more sensitive than conventional biomolecule printing methods. The spots are observed with a fluorescence scanner. By using the CFM to print spots on nanoporous substrates, an additional order of magnitude increase in signal is observed, which leads to high signal‐to‐background ratios, highly saturated spots, and a measurable signal at printing concentrations as low as 1.6 ng mL⁻¹. This technique produces highly concentrated biomolecular spots from dilute samples and significantly increases the sensitivity of sensing platforms.