An optoelectronic Portable Device for Real-Time Nitrate Detection in Water

Abstract

The utilization of autonomous devices has disrupted conventional digital monitoring across diverse domains, particularly impacting environmental monitoring, agriculture, healthcare, as well as healthcare diagnostics. These contemporary autonomous deployables in the field enable dependable testing, gathering of data, and swift transmission of information. Among a variety of prevalent identifying techniques, the spectrophotometric approach stands out for its ability to precisely detect environmental samples at very low concentrations, offering cost-effectiveness and user-friendly operation. Consequently, this study focuses on designing a standalone, handy real-time nitrate concentration detection in water samples, employing readily available light-emitting diodes (LEDs) and photodi-odes with a peak response matching the absorption wavelength of the quartz cuvette in the spectrophotometric detection device. The end product is a portable, extremely sensitive, economical, and energy-efficient device. It integrates a display for offline transfer of information. In a proof-of-concept scenario, nitrate samples were spectrophotometrically tested, detecting nitrate in the linear range of 10–140 mg/L with a limit of detection (LOD) of 0.0072 mg/L. With suitable modifications to the optoelectronic components, the developed spectrophotometric detection platform could potentially be adapted to sense various analytes.