Fabrication of a solution-gated transistor based on valinomycin modified iron oxide nanoparticles decorated zinc oxide nanorods for potassium detection

J Colloid Interface Sci. 2018 May 15:518:277-283. doi: 10.1016/j.jcis.2018.02.041. Epub 2018 Feb 14.

Abstract

There are considerable interests to detect and monitor the abnormal level of minerals in water for avoiding/preventing any toxic effects after consumption. Herein, we report the fabrication of solution-gated field-effect-transistor (FET) based potassium sensor using iron oxide nanoparticles (Fe2O3 NPs) modified directly grown zinc oxide nanorods (ZnO NRs). The Fe2O3 NPs modification of ZnO NRs provided stability to nanorods surface and improved surface area for valinomycin immobilization. As-fabricated potassium sensor (valinomycin-Fe2O3 NPs-ZnO NRs/SiO2/Si) provided enhanced current response with increasing potassium concentration. During sensing measurements, FET sensor showed high sensitivity (4.65 μA/μM/cm2) in the linear range of 0.1 μM to 125 μM, low limit of detection (∼0.04 μM), good stability, excellent reproducibility, and favorable selectivity. Thus, good sensing performance of the FET based potassium sensor presents it as simple, low-cost, and convenient device for selective detection of potassium in solution.

Keywords: Field-effect-transistor; Iron oxide nanoparticle; Potassium; Solution-gated; Valinomycin; Zinc oxide.

MeSH terms

  • Biosensing Techniques / instrumentation
  • Electrochemical Techniques
  • Ferric Compounds / chemistry*
  • Limit of Detection
  • Nanotubes / chemistry*
  • Potassium / analysis*
  • Quantum Dots / chemistry*
  • Reproducibility of Results
  • Silicon Dioxide / chemistry
  • Transistors, Electronic*
  • Valinomycin / chemistry*
  • Zinc Oxide / chemistry*

Substances

  • Ferric Compounds
  • ferric oxide
  • Valinomycin
  • Silicon Dioxide
  • Potassium
  • Zinc Oxide