The present invention is directed to devices and methods using pan-generic antibodies to detect bacteria in a sample. The invention relates to binding assays, especially immunoassays, utilizing a multivalent binding agent immobilized on a particle. The invention also relates to the surprising discovery that increasing the size of the particles improves the sensitivity of the screen. The invention provides, inter alia, a lateral flow device for detecting bacteria in a sample, the device comprising a flow path for the sample and further comprising a pan-generic binding agent specific for other or more bacterial antigens, wherein the pan-generic binding agent is immobilized via a linker on a population of particularly-sized detectable particles; and a capture binding agent that captures the population of particles bound to bacterial antigens, wherein the capture binding agent is immobilized on the flow path, and wherein the population of detectable particles are disposed along the flow path such that the sample contacts the population of detectable particles before contacting the capture binding agent.