A biosensor system, said biosensor system comprising: an apparatus for detecting fluorescent light emitted from a sample, said apparatus (200; 300) comprising: a light source (210; 310, 318), which is configured to emit excitation light of an excitation wavelength towards a sample comprising fluorophores such that fluorescent light is induced; a photo-detector for detecting light incident on the photo-detector; and an interference filter (204; 304) arranged on the photo-detector, and a receiver for receiving a sample holder, wherein the receiver is configured to define a relation between a sample in the sample holder and the interference filter (204; 304); said biosensor system further comprising a sample holder for receiving a fluidic sample and for preprocessing the sample, the sample holder being configured to be arranged in the apparatus (200; 300) for allowing the apparatus (200; 300) to excite fluorescence in the fluidic sample and collect and detect supercritical angle fluorescence from the fluidic sample. wherein the interference filter (204; 304) is configured to selectively collect and transmit light towards the photo-detector based on an angle of incidence of the light towards the interference filter (204; 304), wherein the interference filter (204; 304) is configured to selectively transmit supercritical angle fluorescence from the sample towards the photo-detector and suppress undercritical angle fluorescence from the sample, wherein the receiver is configured to arrange the sample holder in the apparatus and apparatus is configured such that supercritical angle fluorescence is only guided through layers with a refractive index that is equal to or larger than a refractive index of the sample holder. a light source (210; 310, 318), which is configured to emit excitation light of an excitation wavelength towards a sample comprising fluorophores such that fluorescent light is induced; a photo-detector for detecting light incident on the photo-detector; and an interference filter (204; 304) arranged on the photo-detector, and a receiver for receiving a sample holder, wherein the receiver is configured to define a relation between a sample in the sample holder and the interference filter (204; 304); said biosensor system further comprising a sample holder for receiving a fluidic sample and for preprocessing the sample, the sample holder being configured to be arranged in the apparatus (200; 300) for allowing the apparatus (200; 300) to excite fluorescence in the fluidic sample and collect and detect supercritical angle fluorescence from the fluidic sample. wherein the interference filter (204; 304) is configured to selectively collect and transmit light towards the photo-detector based on an angle of incidence of the light towards the interference filter (204; 304), wherein the interference filter (204; 304) is configured to selectively transmit supercritical angle fluorescence from the sample towards the photo-detector and suppress undercritical angle fluorescence from the sample, wherein the receiver is configured to arrange the sample holder in the apparatus and apparatus is configured such that supercritical angle fluorescence is only guided through layers with a refractive index that is equal to or larger than a refractive index of the sample holder.