Fiber Optic Sensors find cancer biomarker

Fiber Optic Sensors detect cancer biomarkerA team of researchers from the Netherlands has developed chip-based fiber optic sensors with integrated laser systems to allow finding low levels of a cancer protein biomarker in a urine sample. Such fiber sensing technology is considered to offer more sensitivity than previous techniques, resulting in noninvasive, inexpensive fiber sensing ways to identify molecules that are responsible for the presence or progression of a disease.

To be more precise, such a fiber optic sensor enables researchers to make label-free detection of S100A4 that is regarded as a protein connected with human tumor development at clinically relevant levels. According to the team, fiber sensing technology promotes faster and more sensitive findings of tumor biomarkers, which favor faster treatment and better results.

The principle of fiber sensor operation is based on “the detection of specific molecules by illuminating the sample with an on-chip microdisk laser system, made with aluminum oxide”. Thus, it is possible to use aluminum oxide doped with ytterbium ions to manufacture a fiber laser that emits in a wavelength outside the laser beam light absorption band of water, while still allowing the accurate finding of biomarkers. Herewith, the frequency or color of the laser beam changes in a detectable way when there is its interaction with the biomarker under consideration.

The laser pump light equipped with the fiber optic sensor performs lasing in a micron into the resonator. Herein, fiber probes are held on the resonator surface capturing the required analytes. Then the laser beam in the ring goes through the fluid, and the attachment of required analytes shows the frequency shifting of laser system emission. Finally, it is possible to accurately measure this shift allowing the detection of minute amounts of analytes flowing over the fiber sensor in a “specific” way.

Despite the fact that fiber optic sensors that monitor laser frequency shifts are not novel, they are often regarded as not easily installed on small, disposable photonic chips, while aluminum oxide can be easily manufactured monolithically on-chip, herewith, it is compatible with conventional electronic manufacture procedures. Such fiber lasers enlarge their opportunities due to unprecedented sensitivity because of much narrower laser beam linewidth than the resonances of passive ring resonators. When other noise sources are overcome, this fiber sensing will enable the finding of minute frequency shifts from biomarkers at very low concentrations.

The developed fiber optic sensor has been already tested in complex liquids such as urine resulting in the detection of S100A4 at concentrations as low as 300 picomolar. Nowadays it is planned to integrate all the relevant optical sources and signal generation components onto the chip to make the fiber sensor even simpler to operate.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Fiber Optic Sensors favors better in photoacoustic microscopy

Fiber Optic Sensors in photoacoustic microscopyA Chinese team of researchers has created a new twist on fiber optic sensors. It promotes the development of a smart flexible photoacoustic imaging technique, which is regarded as a way to enlarge new applications in portable devices, instrumentation, and medical diagnostics.

The operation of the new ultrasound sensor is based on fiber lasers that rely on fiber optic technology to manufacture fiber sensors for photoacoustic imaging. To be more precise, these fiber laser systems apply fiber optic ultrasound determination, utilizing the acoustic effects on laser beam pulses via the thermoelastic effect (temperature changes).

The thing is that traditional fiber optic sensors trace very weak signals due to their high sensitivity via phase measurement. Herewith, this type of fiber sensor can be employed for military purposes to find low-frequency (kilohertz) acoustic waves. Nevertheless, they provide weak operation for “ultrasound waves at the megahertz frequencies used for medical applications because ultrasound waves usually propagate as spherical waves and have a very limited interaction length with optical fibers”.

It should be noted that the main application of the novel fiber sensors is medical imaging, herein, they offer better sensitivity than the piezoelectric transducers in use today. Components of a special ultrasound fiber optic sensor include a portable fiber laser set in the 8-micron-diameter core of a single-mode optical fiber. The standard length of the fiber optic system is only 8 millimeters.

The team uses two highly reflective fiber Bragg grating mirrors written into the fiber core to achieve optical feedback to manufacture the fiber laser. Then they dope the optical fiber with ytterbium and erbium to result in efficient optical gain at 1,530 nanometers. Additionally, a 980-nanometer semiconductor laser operates as the pump laser.

The applications of such fiber laser systems with a kilohertz-order linewidth (the width of the optical spectrum) can include their use as fiber sensors, so they provide a high signal-to-noise ratio. Also, ultrasound detection takes advantage of the combined methods because side-incident ultrasound waves spoil the optical fiber, modulating the laser beam frequency.

The fiber optic sensors based on fiber lasers are highly promising for application in photoacoustic microscopy. The team applies a 532-nm nanosecond pulsed laser to illuminate a sample and excite ultrasound signals leading to a photoacoustic image of the vessels and capillaries. Moreover, it is possible to use the fiber optic system for structural imaging of other tissues and functional imaging of oxygen distribution by employing other excitation wavelengths.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com