Ion-Regulated Signal Amplification Optical Microfiber Interferometric DNA Sensor.

Genetic information sensors play a pivotal role in the biomedical field. The detection of deoxyribonucleic acid (DNA) is achieved experimentally using an optical microfiber interferometric sensor, which operates based on an ion-regulation sensitivity enhancement mechanism. The optical microfiber is fabricated by drawing optical fiber into a diameter of less than 10 μm via the melting and tapering technique.

Vector magnetic field sensor based on coreless D-shaped fiber and magnetic fluid.

A vector magnetic field sensor based on a ferrofluid-encapsulated coreless D-shaped fiber is proposed and demonstrated. The core of the singlemode fiber (SMF) is completely removed by fiber polishing technology, and the remaining part transformed into a multimode interference (MMI) waveguide. The exposed side-polishing plane enable the evanescent field to interact with surrounding magnetic fluid (MF).

Early osteoarthritis diagnosis based on near-infrared spectroscopy combined with aquaphotomics.

Osteoarthritis (OA) is the most common joint disease and the leading cause of disability in elderly individuals. Despite rapid advances in imaging techniques, early OA diagnosis remains a clinical challenge. In the present study, the feasibility of early OA diagnosis was explored via near-infrared spectroscopy (NIRS) combined with aquaphotomics.

Large dynamic strain range slope-assisted Brillouin optical time domain reflectometry based on a graded-index multi-mode fiber.

A slope-assisted Brillouin optical time domain reflectometry system with large dynamic strain range was proposed and demonstrated using graded-index multi-mode fiber (GI-MMF) as sensing fiber. Analysis of the simulated and experimental results indicated that the Brillouin gain spectrum in GI-MMF could be broadened by controlling the coupling efficiency of optical and acoustic modes. The coupling efficiency could be controlled by adjusting lateral offset between single mode fiber (SMF) and GI-MMF.

In-line reflected fiber sensor for simultaneous measurement of temperature and liquid level based on tapered few-mode fiber.

An in-line reflective dual-parameters fiber-optic sensor is proposed in this work, whereas it is experimentally verified by measuring both the liquid level and the local temperature distribution simultaneously. The proposed sensor configuration comprises a single-mode fiber (SMF), a tapered few-mode fiber (TFMF), as well as a silver-coated capillary tube. The extracted experimental results indicate that the liquid level only affects the power of the resonant dips, while having little impact on the wavelength.

Au-NPs signal amplification ultra-sensitivity optical microfiber interferometric biosensor.

An optical microfiber interferometric biosensor for the low concentration detection of sequence-specific deoxyribonucleic acid (DNA) based on signal amplification technology via oligonucleotides linked to gold nanoparticles (Au-NPs) is proposed and experimentally analyzed. The sensor uses a "sandwich" detection strategy, in which capture probe DNA (DNA-c) is immobilized on the surface of the optical microfiber interferometer, the reporter probe DNA (DNA-r) is immobilized on the surface of Au-NPs, and the DNA-c and DNA-r are hybridized to the target probe DNA (DNA-t) in a sandwich arrangement. The dynamic detection of the DNA-t was found to range from 1.

Development of an optical microfiber immunosensor for prostate specific antigen analysis using a high-order-diffraction long period grating.

Fiber-optic biosensors are of great interest to many bio/chemical sensing applications. In this study, we demonstrate a high-order-diffraction long period grating (HOD-LPG) for the detection of prostate specific antigen (PSA). A HOD-LPG with a period number of less than ten and an elongated grating pitch could realize a temperature-insensitive and bending-independent biosensor.

Temperature and liquid refractive index sensor using P-D fiber structure-based Sagnac loop.

A cost-efficient P-D fiber structure-based Sagnac loop sensor is proposed and experimentally demonstrated for measuring temperature and liquid refractive index (RI). The P-D structure is fabricated by fusion splicing a section of polarization-maintaining fiber (PMF) to a piece of multimode D-shaped optical fiber (MMDF). Then the P-D structure is built into a Sagnac loop using a 3dB coupler.