A method for detecting the presence of an analyte in a solution 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, said at least first and second probes (A, B) having spectral optical responses separated from each other, wherein the spectral optical response of a probe is defined as a function of the wavelength by the ratio between the light scattered by the probe in a given solid angle of detection at said wavelength and the amount of light incident on said probe, wherein at least the nanoparticle of the second probe is different from the nanoparticle of the first probe; - contacting the solution suspected of including the analyte with the first and the second probes (A, B) to form a sample solution, wherein the sample solution comprises aggregates comprising the analyte combined with the first and the second probes (A, B); - illuminating the sample solution with a light source having at least a first and a second exciting wavelengths (λ eA, λ eB) different from each other wherein the first and the second wavelength are chosen to get distinct optical responses from the first probe and the second probe respectively when illuminated; - detecting as a function of time the light scattered by the first probe at a first detection wavelength (λ dA) and the light scattered by the second probe at a second detection wavelength (λ dB) different from said first detection wavelength to get a first signal and a second signal respectively; - detecting temporal coincidences between said first signal and second signal; and - detecting the presence of the analyte based on said detection of temporal coincidences. - 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, said at least first and second probes (A, B) having spectral optical responses separated from each other, wherein the spectral optical response of a probe is defined as a function of the wavelength by the ratio between the light scattered by the probe in a given solid angle of detection at said wavelength and the amount of light incident on said probe, wherein at least the nanoparticle of the second probe is different from the nanoparticle of the first probe; - contacting the solution suspected of including the analyte with the first and the second probes (A, B) to form a sample solution, wherein the sample solution comprises aggregates comprising the analyte combined with the first and the second probes (A, B); - illuminating the sample solution with a light source having at least a first and a second exciting wavelengths (λ eA, λ eB) different from each other wherein the first and the second wavelength are chosen to get distinct optical responses from the first probe and the second probe respectively when illuminated; - detecting as a function of time the light scattered by the first probe at a first detection wavelength (λ dA) and the light scattered by the second probe at a second detection wavelength (λ dB) different from said first detection wavelength to get a first signal and a second signal respectively; - detecting temporal coincidences between said first signal and second signal; and - detecting the presence of the analyte based on said detection of temporal coincidences.