Photonic microresonator based sensor for selective nitrate ion detection

Zhongbo Zhang, Xufeng Zhang, Tijana Rajh, Supratik Guha

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Sensing nitrate concentrations in soil with high sensitivity and selectivity using field-deployable compact sensor platforms is a sought-after goal for environment and agriculture applications. This study demonstrates a new optically based nitrate sensing platform based on ion-selective membrane (ISM) functionalized chip-scale photonic micro-ring resonators. Our approach relies upon measurements of resonance shifts in the micro-resonators and leverages the excellent, though little studied, optical properties of ISMs. Using a high-quality micro-ring resonator, a nitrate ion-selective photonic sensor exhibits a detection limit down to 0.1 parts per million (ppm) and enables nitrate concentration measurements in the 1−100 ppm level, appropriate for soil science and agriculture. Importantly, the sensor also shows high selectivity over other competing anions in soil, such as Cl and NO2. We argue that this chip-scale approach can be incorporated into compact sensor platforms.

Original languageEnglish (US)
Article number129027
JournalSensors and Actuators, B: Chemical
StatePublished - Feb 1 2021
Externally publishedYes


  • Integrated photonic sensor
  • Ion selective membrane
  • Micro-ring resonator
  • Nitrate sensor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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