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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #386396

Research Project: Improving the Sustainability of Irrigated Farming Systems in Semi-Arid Regions

Location: Water Management and Systems Research

Title: Printed organic electrochemical transistors with internal ion reservoirs for detecting macronutrients in whole plant sap

Author
item STRAND, ELLIOT - University Of Colorado
item BIHAR, ELOISE - University Of Colorado
item Gleason, Sean
item HAN, SANGGIL - University Of Cambridge
item SCHREIBER, SAMUEL - University Of Cambridge
item RENNY, MEGAN - University Of Colorado
item MALLIARAS, GEORGE - University Of Cambridge
item MCLEOD, ROBERT - University Of Colorado
item WHITING, GREGORY - University Of Colorado

Submitted to: Science and Technology of Advanced Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2021
Publication Date: 12/28/2021
Citation: Strand, E.J., Bihar, E., Gleason, S.M., Han, S., Schreiber, S.W., Renny, M.N., Malliaras, G.G., McLeod, R.R., Whiting, G.L. 2021. Printed organic electrochemical transistors with internal ion reservoirs for detecting macronutrients in whole plant sap. Science and Technology of Advanced Materials. https://doi.org/10.1002/aelm.202100853.
DOI: https://doi.org/10.1002/aelm.202100853

Interpretive Summary: We developed organic (non-metal) sensors that can be implanted in the living vascular tissues of plants. We tested sensor sensitivity to detect potassium ions in the sap extracted from six plant species against measurements made via standard methods (high performance liquid chromatography). Sensor accuracy and precision was within acceptable limits, exhibiting both high sensitivity and a low detection limit. The performance of these printed devices enable their use for high-throughput, low-cost plant health monitoring in agricultural and ecological applications.

Technical Abstract: Low-cost biosensors that can monitor plant nutritional levels in real-time and be widely distributed over large areas will be critical for better understanding plant health and improving precision agriculture decision making. In this work, fully printed, mechanically flexible, and ion selective organic electrochemical transistors (OECTs) that can detect macronutrient concentrations in whole plant sap are described. Potassium, the most concentrated cation in plants, was selected as the target analyte as it plays a critical role in plant growth and development. Transconductance of the OECTs was dramatically improved by doping the printable PEDOT:PSS ink with sorbitol, providing a maximum transconductance of 5.0 mS. The ion sensors demonstrate high current sensitivity (170 µA dec-1), a super-Nernstian sensitivity (99 mV dec-1) and a low limit of detection (10 µM). These OECT ion sensors can be used to determine potassium concentration in whole sap and sap-like aqueous environments demonstrating a log-linear response within the expected physiological range of cations in plants. The performance of these printed devices enable their use for high-throughput, low-cost plant health monitoring in agricultural and ecological applications.