Label-Free Detection of Cancer Biomarkers Using an In-Line Taper Fiber-Optic Interferometer and a Fiber Bragg Grating

Citation

Sun, D.; Ran, Y.; Wang, G. Label-Free Detection of Cancer Biomarkers Using an In-Line Taper Fiber-Optic Interferometer and a Fiber Bragg Grating. Sensors 2017, 17, 2559.

Keywords

  • fiber taper interferometer
  • FBG
  • optical biosensor
  • cancer biomarker

Brief

A compact and label-free optical fiber sensor based on a taper interferometer cascaded with a fiber Bragg grating (FBG) is proposed and experimentally demonstrated for detection of a breast cancer biomarker (HER2).

Summary

This 2017 article in Sensors by Sun, Ran, and Wang describes a new optical fiber sensor for detecting the breast cancer biomarker HER2. The sensor uses a tapered fiber-optic interferometer, which is highly sensitive to changes in refractive index (RI), making it ideal for detecting the presence of target molecules. To account for temperature fluctuations, the sensor also incorporates a fiber Bragg grating (FBG), which is insensitive to RI changes but responds to temperature variations. The FBG acts as a built-in thermometer.

How it works:

  • The sensor surface is specially treated to bind to HER2 antibodies.
  • When HER2 biomarkers are present, they bind to the antibodies, changing the RI near the sensor surface.
  • This RI change causes a shift in the wavelength of light passing through the tapered fiber-optic interferometer.
  • The FBG simultaneously measures any temperature changes that might also affect the interferometer's readings.

Key findings:

  • The sensor can detect HER2 concentrations as low as 2 ng/mL.
  • The FBG effectively compensates for temperature fluctuations, ensuring accurate biomarker detection.

Significance:

This new sensor offers a promising tool for early breast cancer diagnosis. It's compact, label-free, and highly sensitive.

Origin: https://www.semanticscholar.org/reader/8899ec56d205942dceaa86a7207c5456a38bf6eb
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