The project's overall aim is the fabrication of ultra-sensitive immunoturbidimetric tests. To achieve this purpose, it proposes a strategy for on the basis of polystyrene beads which are functionalized with a reactive group, in combination with the suppression of non-specific interactions by means of a polymer coating. Through comprehensive evaluation and optimization of the modified polystyrene beads they will develop four specific test for D-dimer, procalcitonin, insulin and T4 thyroid hormone.