Rapid Determination of Extra Virgin, Sunflower, and Rapeseed Oils: An Ultraviolet-Sensitive Single-Photon Avalanche Diode Approach

Single-photon detectors have shown significant potential in medical and depth-sensing applications. We demonstrate the first instance of oil discrimination among olive oil, extra virgin olive oil (EVOO), sunflower, and rape-seed oils using an ultraviolet (UV) sensitive CMOS single-photon avalanche diode (SPAD) pixel. The device measures the photon detection rate (PDR) of target samples held in a UV-transmissive quartz cuvette. By employing LED illumination at 260, 300, 355, 375, 420, 460, 540, and 585 nm, alongside a 520 nm laser, the PDR profiles of EVOO, rapeseed, sunflower, and blended oils reveal distinct absorption characteristics. These findings validate the feasibility of using silicon complementary metal-oxide-semiconductor (CMOS) UV SPADs for the detection and classification of edible oils, while offering a potential framework for the quality assessment of liquids that exhibit specific spectral signatures under UV and visible light.