An in-fiber integrated optofluidic device based on an optical fiber with an inner core

Abstract

A new kind of optofluidic in-fiber integrated device based on a specially designed hollow optical fiber with an inner core is designed. The inlets and outlets are built by etching the surface of the optical fiber without damaging the inner core. A reaction region between the end of the fiber and a solid point obtained after melting is constructed. By injecting samples into the fiber, the liquids can form steady microflows and react in the region. Simultaneously, the emission from the chemiluminescence reaction can be detected from the remote end of the optical fiber through evanescent field coupling. The concentration of ascorbic acid (AA or vitamin C, Vc) is determined by the emission intensity of the reaction of Vc, H2O2, luminol, and K3Fe(CN)6 in the optical fiber. A linear sensing range of 0.1-3.0 mmol L(-1) for Vc is obtained. The emission intensity can be determined within 2 s at a total flow rate of 150 μL min(-1). Significantly, this work presents information for the in-fiber integrated optofluidic devices without spatial optical coupling.

Optical Fiber Optofluidic Bio‐Chemical Sensors: A Review

“…The types of optical fibers that can be used for OFOF sensors based on fluorescence detection are diverse, including ECF, [21,103] SCF, [51,61] HSCF, [27,47] silica capillary fiber, [291] capillary optical fiber with ring waveguide, [170] HCMF, [77] HCPCF, [42] and tapered optical fiber that can be integrated into the microfluidic channel. [288] The ECF with suspended micron core that is partially exposed to the external environment, allows the sensing probe to be continuously cleaned, dried, and refilled during the measurement process.…”

“…[58] Later, based on the fiber, the author prepared some compact OFOF sensors for the detection of ascorbic acid concentration and nitrite concentration respectively. [27,47] In short, the hollow channels inside the HTCF and HSCF can be used as biochemical reaction microcavities, where the analyte interacts with the evanescent wave around the optical fiber core, which can realize the in-fiber biochemical measurement.…”

“…First, based on the fluorescence quenching effect, the concentration of quencher was measured. [ 27,47,51 ] Second, derivatize these analyte molecules as fluorescent compounds, making them part of the chemical reactions that ultimately produce fluorescent compounds. [ 103,289 ] Third, by means of fluorescent dye labelling, they are transformed into a fluorescent substance suitable for measurement [290] …”

“…For example, in 2014, Yang et al designed and prepared an in-fiber integrated optofluidic device based on the combination of specially designed hollow optical fiber (HOF) with an inner core and chemiluminescence reaction principle, and used it for the detection of ascorbic acid concentration. [27] Recently, several excellent reviews on OFOF sensors have been published, including optofluidic refractometers, optofluidic sensors based on MOF and optofluidic technology based on optical force and photothermal effects. [28][29][30] In the past few decades, optical bio-chemical sensors have been widely exploited in medical diagnosis, environmental monitoring, food safety, and other fields.…”

Ultra-sensitive chemical and biological analysisviaspecialty fibers with built-in microstructured optofluidic channels

“…2) Complex techniques in creating in-line liquid access. Currently, making liquid sideaccess requires the assistance of either a precisely fabricated connecter placed in-between the PCF and SMFs 12 or using complicated micro-machining techniques, such as femtosecond/CO2 laser with high-accuracy positioning stages, 17,18 to form holes on the fiber surface.…”