DNA microarrays are promising tools for fast and highly parallel DNA detection. However, the substrate modification (as a prerequisite for capture DNA binding)often leads to inhomogeneous surfaces and/or nonspecific binding of the labeled DNA. Due to their interesting physical properties gold nanoparticles are of growing interest as labels in biomolecular detection. Especially for point-of-care analyses they may overcome some of the drawbacks of fluorescence detection based on their simple optical or electrical readout. Thereby, specific metal deposition on the nanoparticles is of outstanding importance for signal enhancement. However, a broad understanding of the influence of enhancement solution, incubation time, and seed size is still lacking as well as the growth characteristics of conductive metal labels in electrode gaps, especially with regard to electrical detection schemes.