Integrated device having an array of photodetectors and an array of sample sites

An integrated device for detecting emissions from a sample (70) involves forming an array of photo detectors (20) for detecting the emissions and forming an array of sites for receiving the sample such that edges of the sites are defined by edges of the photo detectors. A side wall of a site using a diode can provide a side wall suitable for ink- jet printing samples such as biomolecules with no extra mask steps. This helps enable the sample and the photo detector to be mutually aligned more easily or more cost effectively than conventional devices where the site for receiving the sample is formed separately from the photo detector. The detection can be in any direction, such as lateral or vertical detection. Lateral optical detection with a shielded photodiode means only light emanating from one pixel/spot is detected. A light source (200) to stimulate emissions can be integrated