Printed Graphene Electrochemical Biosensors Fabricated by Inkjet Maskless Lithography for Rapid and Sensitive Detection of Organophosphates

John A. Hondred, Joyce C. Breger, Nathan J. Alves, Scott A. Trammell, Scott A. Walper, Igor L. Medintz, Jonathan C. Claussen

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Solution phase printing of graphene-based electrodes has recently become an attractive low-cost, scalable manufacturing technique to create in-field electrochemical biosensors. Here, we report a graphene-based electrode developed via inkjet maskless lithography (IML) for the direct and rapid monitoring of triple-O linked phosphonate organophosphates (OPs); these constitute the active compounds found in chemical warfare agents and pesticides that exhibit acute toxicity as well as long-term pollution to soils and waterways. The IML-printed graphene electrode is nano/microstructured with a 1000 mW benchtop laser engraver and electrochemically deposited platinum nanoparticles (dia. ∼25 nm) to improve its electrical conductivity (sheet resistance decreased from ∼10 000 to 100 Ω/sq), surface area, and electroactive nature for subsequent enzyme functionalization and biosensing. The enzyme phosphotriesterase (PTE) was conjugated to the electrode surface via glutaraldehyde cross-linking. The resulting biosensor was able to rapidly measure (5 s response time) the insecticide paraoxon (a model OP) with a low detection limit (3 nM), and high sensitivity (370 nA/μM) with negligible interference from similar nerve agents. Moreover, the biosensor exhibited high reusability (average of 0.3% decrease in sensitivity per sensing event), stability (90% anodic current signal retention over 1000 s), longevity (70% retained sensitivity after 8 weeks), and the ability to selectively sense OP in actual soil and water samples. Hence, this work presents a scalable printed graphene manufacturing technique that can be used to create OP biosensors that are suitable for in-field applications as well as, more generally, for low-cost biosensor test strips that could be incorporated into wearable or disposable sensing paradigms.

Original languageEnglish (US)
Pages (from-to)11125-11134
Number of pages10
JournalACS Applied Materials and Interfaces
Volume10
Issue number13
DOIs
StatePublished - Apr 4 2018

Keywords

  • electrochemical biosensor
  • graphene
  • inkjet printing
  • paraoxon
  • pesticide
  • phosphotriesterase

ASJC Scopus subject areas

  • Materials Science(all)

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