Device to detect at least an analyte, comprising a transparent substrate (2), having a first surface (3) with which a light source (7) is associated, and a second surface (4) on which a plurality of biological protein probes (12) are disposed, a layer (6) of polymer being interposed between said second surface (4) and said biological protein probes (12). A marker (fluorophore) is associated with said analyte, having determinate characteristics of fluorescence and/or phosphorescence correlated to the emission wavelength of the light source (7). Said light source (7) is suitable to emit a light radiation in a range of wavelengths equal to 400-550 nm, inside which range the absorption peak of said marker (fluorophore) used is comprised. The value of the distance (“s”) between the wavelength corresponding to the absorption peak of the marker (fluorophore) and the wavelength corresponding to the emission peak of fluorescence (phosphorescence) is comprised between 25 and 150 nm.