Optical measurement method for molecular detection using relaxation measurement in optically anisotropic nanoparticles and device for performing the method

A method for molecular detection via one of determination or a measurement of a relaxation behavior of particles selected from the group consisting of microparticles and nanoparticles, that are one of dispersed or suspended in a fluid medium, on a surface of the particles one of target molecules, molecule sequences, molecule parts or organisms are one of bound specifically or nonspecifically, which comprises the steps of:

• providing the particles that have been occupied to be alignable, at least predominantly, in a spatial direction, in the dispersion or the suspension, as a result of an influence of an external stimulus, for the determination of the relaxation behavior, in the suspension or the dispersion being used the particles have optical anisotropy, besides their geometric positional alignability, where the optical anisotropy of the particles originates from an anisotropic plasmon excitation in the particles;
• converting the particles, in the dispersion or the suspension, either from an at first stochastic, statistically disordered, unaligned state, into a finally at least predominantly uniformly aligned state, or vice versa;
• irradiating in light selected from the group consisting of linear light, polarized light and nonpolarized light into the suspension or the dispersion;
• determining one of a behavior or properties of the dispersion or the suspension in each of the two states and/or between the two states resulting in a determined relaxation behavior by subjecting the light to an optometric analysis where the light is one of:
• taken up directly from the suspension or the dispersion in an irradiation direction in or by absorption;
• the light exiting as scattered light at an angle with respect to the irradiation direction;
• or
• the light that is emitted by excitation;
• performing the optometric analysis at least one of immediately, after the light passes through a polarization filter connected after the dispersion or the suspension, or only after a forced passage through a polarization filter which is connected after the dispersion or the suspension through which the light passes;
• and
• deriving from the determined relaxation behavior at least one of a concentration, a size and a property of one of the target molecules, the molecule sequences, the molecule parts and the organisms bonded to the particles.