A method for detecting the presence of an analyte (1) in a solution (2) comprising: providing at least a first and a second probes (A, B) different from each other, each probe (A,B) comprising a nanoparticle conjugated with a receptor specific to the analyte (1); contacting the solution (2) suspected of including the analyte (1) with the first and the second probes (A, B) to form a sample solution (3), wherein the sample solution (3) comprises aggregates (4) comprising the analyte (1) combined with the first and the second probes (A, B); illuminating the sample solution (3) with a light source having at least a first and a second exciting wavelengths (λeA, λeB) different from each other wherein the first and the second wavelength are chosen to get specific optical responses from the first probe (A) and the second probe (B) respectively when illuminated; detecting as a function of time the light scattered by the first probe (A) at a first detection wavelength (λdA) and the light scattered by the second probe (B) at a second detection wavelength (λdB) to get a first signal and a second signal respectively; and detecting temporal coincidences between said first signal and second signal.