Methods, sampling device and apparatus for terahertz imaging and spectroscopy of coated beads, particles and/or microparticles

A method of analyzing or imaging beads, particles or microparticles, comprising:

• a) loading one or more beads, particles or microparticles onto a bead holder, the bead holder comprising a tray having a substantially planar upper surface and one or more offsets above or below the substantially planar upper surface, each offset being configured to hold one of the beads, particles or microparticles and having a height or depth configured to minimize or eliminate interference between reflections of the terahertz radiation from the tray and reflections of the terahertz radiation from the bead, particle or microparticle in or on the offset;
• b) loading the bead holder into a terahertz spectroscopy and/or imaging system;
• c) irradiating the one or more beads, particles or microparticles in the bead holder with pulses of terahertz radiation;
• and
• d) evaluating and/or analyzing data and/or information from reflections of the pulses of terahertz radiation from the one or more beads, particles or microparticles in the bead holder.