Printable transistors for wearable sweat sensing

Melanie Rudolph, Jonathan K. Harris, Erin L. Ratcliff

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Human performance monitoring (HPM) devices for sweat sensing in both civilian and military uses necessitate chemical sensors with low limits of detection, rapid read out times, and ultra-low volumes. Electronic and electrochemical sensing mechanisms for biomarker identification and quantification are attractive for overall ease of use, including robust, portable, fast readout, and simple operation. Transistors have the high signal gain required to sense low concentrations (μM to pM) at low volumes (μL to nL) in real-time (<1 minute), metrics not achievable by benchtop analytical techniques. Two main challenges currently prohibit the realization of transistor-based biosensors: i) the need for printed devices for low-cost, disposable sensors; and ii) the need to overcome diminished sensitivity in high ionic strength solutions. In this proof-of-concept work, we demonstrate organic electrochemical transistors (OECT) as a promising low cost, printable device platform for electrochemical detection of biomarkers in high ionic strength environments. This work focuses on how the materials choice and functionality impacts the electrochemical and sensor and transducer performance and determining the feasibility of reducing the size of the sensor to nanoliter volume detection. Initial studies target dopamine. Detection limits for simple electrochemical approaches using platinum or glassy carbon electrodes remain relatively high (∼ 1-10 ng/mL or 50 nM). Using an OECT, we demonstrate an initial detection level of dopamine at ∼ 10 pg/mL achieved without any selective binding modifications to the gate electrode at gate voltages below 1 V.

Original languageEnglish (US)
Title of host publicationSmart Biomedical and Physiological Sensor Technology XV
EditorsBrian M. Cullum, Douglas Kiehl, Eric S. McLamore
ISBN (Electronic)9781510627055
StatePublished - 2019
EventSmart Biomedical and Physiological Sensor Technology XV 2019 - Baltimore, United States
Duration: Apr 15 2019Apr 16 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSmart Biomedical and Physiological Sensor Technology XV 2019
Country/TerritoryUnited States


  • Organic bioelectronics
  • Organic electrochemical transistor
  • Wearable printable sensors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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