Reagent-less spectroscopy towards NPK sensing for hydroponics nutrient solutions

Bibliographic reference: 

Silva, F.M.; Queirós, C.; Pinho, T.; Boaventura, J.; Santos, F.; Barroso, T.G.; Pereira, M.R.; Cunha, M.; Martins, R.C. Reagent-less spectroscopy towards NPK sensing for hydroponics nutrient solutions, Sensors and Actuators B: Chemical, 395, 2023, 134442, ISSN 0925-4005, https://doi.org/10.1016/j.snb.2023.134442