510 KB0 KB2026Lukšič, MihaRozman, MartinTiringer, Uršaštevilka:4letnik:93str. 195-205ISSN:0013-5852COBISSID_HOST:301638147URN:URN:NBN:SI:doc-6X16QBSNslElektrotehniška zveza SlovenijeElektrotehniški vestnikCu/ESOCu/GCEelectrochemical impedance spectroscopyelektrokemijska impedančna spektroskopijahidroponski sistemhydroponicsnitratnitratenitritnitriteElektrokemijski senzorji Cu/ESO za sprotno spremljanje nitratov in nitritov v hidroponskih sistemih| pregled stanja in razvojnih izzivov|Closed-loop hydroponic systems enable efficient use of water and fertilizers, but routine monitoring of nutrient solutions is still largely based on pH and electrical conductivity measurements. Such parameters do not provide direct information on nitrate (NO3?) and nitrite (NO2?), which are important indicators of plant nutrition and nutrient solution stability. This review evaluates electrochemical approaches for nitrate and nitrite monitoring, with particular emphasis on copper-modified glassy carbon electrodes (Cu/GCE). Conventional analytical methods are compared with electrochemical alternatives suitable for online applications. The review discusses copper electrodeposition, the formation of Cu nanostructures, electrochemical reduction mechanisms, voltammetric detection methods, and the role of electrochemical impedance spectroscopy (EIS). Particular attention is given to the influence of electrode morphology, pH, dissolved oxygen, and matrix composition on sensor performance. Copper nanostructures improve the electrochemical response towards nitrate and nitrite and represent a promising basis for sensor development. EIS is particularly useful formonitoring electrode condition and interfacial processes, although its direct application for selective nitrate and nitrite quantification in complex hydroponic matrices remains insufficiently validated. The review highlights that most published Cu-based sensors have been evaluated in simplified laboratory media, whereas validation in real hydroponic nutrient solutions is still limited. Future research should therefore focus on long-term stability, interference effects, standardized testing protocols, and validation under realistic operating conditions. Cu/GCE sensors offer a favourable compromise between analytical performance, reproducibility, regenerability, and suitability for integration into online hydroponic monitoring systems. Their successful implementation will depend not only on advances in electrode materials but also on robust validation and integration with modern monitoring and control systemsZaprti hidroponski sistemi omogočajo visoko učinkovitost rabe vode in gnojil, vendar njihovo upravljanje še vedno večinoma temelji na meritvah pH in električne prevodnosti. Tak pristop ne omogoča neposrednega spremljanja nitratov (NO3?) in nitritov (NO2?), ki sta ključna parametra za rast rastlin, stabilnost hranilne raztopine in okoljsko varnost sistema. Članek kritično obravnava elektrokemijske pristope za detekcijo NO3? in NO2? s poudarkom na z bakrom modificiranih elektrodah iz steklastega ogljika (Cu/ESO; v angleški literaturi Cu/GCE). Primerjamo klasične referenčne metode in elektrokemijske alternative ter analiziramo mehanizme elektrodepozicije Cu, nastanek nanostruktur, pH-odvisnost redukcijskih poti in vpliv morfologije na analitski odziv. Izpostavimo razliko med rezultati, doseženimi v poenostavljenih laboratorijskih medijih, in zahtevnejšo uporabo v realnih hidroponskih raztopinah. Cu-nanostrukture znižajo prenapetost redukcije nitrata in nitrita ter izboljšajo občutljivost voltametričnih metod. Elektrokemijska impedančna spektroskopija (EIS) je predvsem komplementarna tehnika za spremljanje stanja elektrode in medfaznih procesov, medtem ko neposredna kvantifikacija NO3?/NO2? v večionskih hidroponskih matricah še ni zadostno validirana. Za prehod senzorjev Cu/ESO v realne hidroponske sisteme bodo ključni validacija v dejanskih hranilnih raztopinah, standardizirano poročanje merilnih pogojev, kompenzacija vplivov pH, temperature, kisika in interferentov ter primerjava z referenčnimi metodami, kot je ionska kromatografijaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaElektrotehniška zveza Slovenije