Methods and systems of quantifying a target material in solution include detection of a size change of a hybridized nanoparticle. In particular, the examples include functionalizing a plurality of nanoparticles to adapt the nanoparticles to hybridize with a species-specific target material, measuring the size of the functionalized nanoparticles to predetermine a standard distribution of non-hybridized nanoparticles, introducing the functionalized nanoparticles in a solution containing species-specific target materials and/or non-target materials, and hybridizing the functionalized nanoparticles with the species-specific target material if present in the solution. The size of the nanoparticles in solution are then measured after hybridization, and the presence or non-presence of the species-specific target material is detected and/or quantified by comparing the measured size of the nanoparticles after hybridization to the standard distribution of non-hybridized nanoparticles.