Abstract:
A diagnostic device includes a photodiode (2) formed by a body (10) of semiconductor material having a first surface (6a), an integrated optical structure (30) on the first surface and having a second surface (34a), and at least one detection region (50) on the second surface. The at least one detection region includes at least one receptor (52) that binds to a corresponding target molecule (MB) that can be mated with a corresponding marker (54), which, when excited by radiation having a first wavelength (λe), emits radiation having a second wavelength (λf) that can be detected by the photodiode. The integrated optical structure includes at least a first layer (34, 62) of a first material having a first refractive index (n1). The first layer has a thickness substantially equal to an integer and odd multiple of one fourth of the first wavelength (λe) divided by the first refractive index.