A method of detecting particles, e. g. proteins, after separation of particles based on their specific features, e.g. charge, size, shape, density, as series of single light scattering events created by the individual particles is described. The particles are separated from each other along the separation path and particles have specific arrival times at the target side depending on the particle features. The detecting step comprises an interferometric sensing of the light scattered at individual particles bound or transient in the detection volume. Parameters of the scattering light signals e.g. the interferometric contrast are analyzed for obtaining specific particle features, e.g. size, mass, shape, charge, or affinity of the particles. Furthermore, a detection apparatus being configured for detecting particles is described.