Abstract: A method has been invented to detect and identify airborne pathogens and their properties based on the affinity of water-soluble quantum dot bioconjugates. A plurality of different sized quantum dot bioconjugates, where each size is conjugated with a different functional biological material or biomaterial, are combined in solution to form an assay. The airborne pathogens are then dissolved in the solution, where they contact the quantum dot bioconjugates. If the quantum dot bioconjugates have an affinity to the dissolved pathogens they will bind together. The quantum dots bound to the pathogens are then separated from those that remain unbound by filtration. An activation light source is then used to excite the quantum dots present in the filtered solution.