Particle detection method using refraction index measurement, comprises reversibly immobilizing particles on sensor surface with ion exchanger

摘要

Particles are immobilized by an ion exchanger (3) on a sensor surface (2) and then mobilized. The changes in the refraction index of the surface are measured. A method for detecting a particle comprises measuring the refraction index on a sensor surface provided with an ion exchanger for binding the particle. The sensor surface forms part of a detection cell including a means for determining the change in refraction index caused by the presence of the particle. The detection method comprises the following steps: (a) a sample is allowed to flow over the sensor surface under conditions in which one or more of the particles to be detected will be immobilzed on the ion exchanger; (b) altering the conditions so that at least some of the particles (if present) become mobilized again ; (c) removing the mobilized particles from the sensor surface; and (d) measuring and recording the changes in the refraction index. Independent claims are also included for: (a) the sensor surface, provided with an ion exchanger in the form of a derivative of cellulose, dextran or another polysaccharide having a number average molecular weight (Mn) of 1-500 kg/mole; (b) a detection cell with this sensor surface; and (c) a device comprising the detection cell, a light source (4) emitting a beam of light (5) at an angle to the sensor surface and a refraction index change measuring device.