a system and method for detecting the presence of submicron sized particles in a sample taken from the environment includes a collecting a sample from the environment and purifying and concentrating the submicron particles in a sample based on the size of the particles . the purified and concentrated particles are detected with an apparatus which includes an electrospray assembly having an electrospray capillary , a differential mobility analyzer which receives the output from the capillary , and a condensation particle device for counting the number of particles that pass through the differential mobility analyzer . the system is intended to collect a sample containing submicron size particles having a size range of from greater than 350 nanometers to about 1000 nanometers and wherein the particles include viruses , prions , viral subunits , viral cores of delipidated viruses , plant viruses , standard particles used for calibrating equipment , coated particles , spherical particles , metallic - core shelled particles , polymers , fluorescent microspheres , powders , nanoclusters , particles produced as a result of manufacturing processes , and portions of bacteria ;