2020/02/26 by Mauro Buttafava, Buttafava, Mauro, Federica Villa +21 · 1 citation
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Advanced Biosensing Techniques and Applications #Advanced Optical Sensing Technologies #Biosensors and Analytical Detection #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Optics (physics.optics)
paper · pdf · doi:10.48550/arxiv.2002.11443
openalex publication_date 2020/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Fluorescence microscopy and derived techniques are continuously looking for\nphotodetectors able to guarantee increased sensitivity, high spatial and\ntemporal resolution and ease of integration into modern microscopy\narchitectures. Recent advances in single photon avalanche diodes (SPADs)\nfabricated with industry-standard microelectronic processes allow the\ndevelopment of new detection systems tailored to address the requirements of\nadvanced imaging techniques (such as image-scanning microscopy). To this aim,\nwe present the complete design and characterization of two bidimensional SPAD\narrays composed of 25 fully independent and asynchronously-operated pixels,\nboth having fill-factor of about 50% and specifically designed for being\nintegrated into existing laser scanning microscopes. We used two different\nmicroelectronics technologies to fabricate our detectors: the first technology\nexhibiting very low noise (roughly 200 dark counts per second at room\ntemperature), and the second one showing enhanced detection efficiency (more\nthan 60% at a wavelength of 500 nm). Starting from the silicon-level device\nstructures and moving towards the in pixel and readout electronics description,\nwe present performance assessments and comparisons between the two detectors.\nImages of a biological sample acquired after their integration into our custom\nimage-scanning microscope finally demonstrate their exquisite on-field\nperformance in terms of spatial resolution and contrast enhancement. We\nenvisage that this work can trigger the development of a new class of\nSPAD-based detector arrays able to substitute the typical single-element sensor\nused in fluorescence laser scanning microscopy.\n