Biomedical soft contact-lens sensor for in situ ocular biomonitoring of tear contents

Biomed Microdevices. 2011 Aug;13(4):603-11. doi: 10.1007/s10544-011-9530-x.


A soft contact-lens biosensor (SCL-biosensor) for novel non-invasive biomonitoring of tear fluids was fabricated and tested. Wearing a biosensor on eye enabled the in situ monitoring of tear contents. The biosensor has an enzyme immobilized electrode on the surface of a polydimethyl siloxane (PDMS) contact lens. The SCL-biosensor was fabricated using microfabrication techniques for functional polymers (PDMS and 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer). In investigation of in vitro characterization, the SCL-biosensor showed excellent relationship between the output current and glucose concentration from 0.03 to 5.0 mmol·L(-1), with a correlation coefficient of 0.994. The calibration range covered the reported tear glucose concentrations (0.14 mmol·L(-1)). Based on the result, ocular biomonitoring with the SCL-biosensor was carried out. The SCL-biosensor well worked both in the static state and the dynamic state. The tear glucose level of rabbit was estimated to 0.12 mmol·L(-1) at first and then the tear turnover was successfully calculated to be 29.6 ± 8.42% min(-1). The result indicated that SCL-biosensor is useful for advanced biomonitoring on eye.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomedical Technology / instrumentation*
  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods
  • Calibration
  • Contact Lenses, Hydrophilic*
  • Dimethylpolysiloxanes / chemistry
  • Eye / metabolism
  • Glucose / analysis
  • Methacrylates / chemistry
  • Microtechnology / methods
  • Phosphorylcholine / analogs & derivatives
  • Phosphorylcholine / chemistry
  • Rabbits
  • Tears / chemistry*
  • Vision, Ocular


  • Dimethylpolysiloxanes
  • Methacrylates
  • Phosphorylcholine
  • 2-methacryloyloxyethyl phosphorylcholine
  • baysilon
  • Glucose