1. Apparatus for detecting metallic nanoparticles on a substrate, with or without chemical signal amplification of the metallic nanoparticles, the apparatus comprising in combination: a substrate holder for holding the substrate, the substrate holder being stationary; a processor; a memory device in communication with the processor; an imaging module in communication with the processor, the imaging module being stationary; an illumination module for illuminating the substrate; a power module; an input module for receiving operator instructions; and an output module for outputting whether metallic nanoparticles have been detected, wherein the imaging module and the substrate holder are proximate to one another, and wherein the processor controls the imaging module, illumination module input module and output module.