Study on measurement of nanoparticles size based on fluorescence polarization (1st Report) - Development of rotational diffusion coefficient measurement system using fluorescent DNA probe - Development o

Nanoparticles are attractive materials in the area of nanotechnology, and there is a need to measure the particle size accurately and easily. We suggest a novel particle sizing method based on fluorescence polarization. Particle size evaluation can be achieved from measuring the rotational diffusion coefficient which is sensitive to the particle size. We develop the rotational diffusion coefficient measurement system using fluorescent DNA probe. We verify the feasibility of proposed method by a fundamental experiment. We measure the rotational diffusion coefficient of gold nanoparticle whose diameter is 8.2nm. The rotational diffusion coefficient decreases by 50% compared to the reference value in the measuring range. The result indicates that nanoparticle, whose diameter is as small as 8.2nm, can be measured.