An overview of applications of fiber-optic biochemical sensor in microfluidic chips was carried out with a specific focus on different fiber-optic sensors used on chip, detection methods and ...biochemical application. First, the structure and sensing mechanism of different fiber-optic sensors used on chip was introduced. Second, optical detection methods in microfluidic chips combined with optical fibers and the advantages and disadvantages of each method were introduced and analyzed in detail. Then, applications of fiber-optic biochemical sensors in microfluidic sensor chips in detecting nucleic acids, proteins, cells, chemicals and microfluidic flow rate were classified and introduced, and different fiber-optic biochemical sensors in microfluidic chip were compared. Finally, a prospect of future development of fiber-optic biochemical sensor combined with microfluidic chip was addressed.
•An overview of applications of fiber-optic biochemical sensor in microfluidic chips was carried out.•The structure and sensing mechanism of different fiber-optic sensors used on chip was introduced.•Microfluidic chips combined with optical fibers were introduced and analyzed in detail.•Applications of fiber-optic biochemical sensors in microfluidic chips were discussed.
In this study, a fiber-optic sensor based on Fabry-Perot interferometer (FPI) and Mach-Zehnder interferometer (MZI) cascaded structure is proposed and demonstrated for seawater salinity and ...temperature simultaneous measurements. A section of hollow-core fiber (HCF) with a U-shaped defect is spliced between single-mode fibers to form FPI. The U-shaped defect inscribed by the femtosecond laser facilitates liquid flow-through and enables the salinity measurement. The MZI composes of laser-induced optical waveguides written in the cladding of the coating-retained single-mode fiber. There is an interaction between the evanescent field of the in-fiber waveguides and the coating due to the written waveguide is close to the cladding-coating interface. Part of the incident light is reflected by HCF to form the FPI spectrum, while the transmitted light in the core is coupled to the written waveguides and guided along the cladding region, which finally returned to the core to obtain the MZI spectrum. Theoretical analysis and experimental verification are carried out, and the results show that the proposed sensor offers a salinity sensitivity of 0.244 nm/‰ and a temperature sensitivity of − 2.767 nm/℃. Such a cascaded interferometer has advantages of high sensitivity and compact size, which is expected to be widely used in seawater parameter measurements due to the flexible structure and precise control.
•An F-P and M-Z interferometer cascaded fiber-optic sensor is proposed for salinity and temperature measurements.•F-P interferometer is formed by splicing a section of hollow-core fiber with a femtosecond laser-inscribed U-shaped defect.•M-Z interferometer composes of laser-induced optical waveguides written in the cladding of the fiber.•The sensor realizes simultaneous salinity and temperature measurements with sensitivities of 0.244 nm/‰ and − 2.767 nm/℃.
In spite of the competitive performance at room temperature, the development of sodium‐ion batteries (SIBs) is still hindered by sluggish electrochemical reaction kinetics and unstable ...electrode/electrolyte interphase under subzero environments. Herein, a low‐concentration electrolyte, consisting of 0.5M NaPF6 dissolving in diethylene glycol dimethyl ether solvent, is proposed for SIBs working at low temperature. Such an electrolyte generates a thin, amorphous, and homogeneous cathode/electrolyte interphase at low temperature. The interphase is monolithic and rich in organic components, reducing the limitation of Na+ migration through inorganic crystals, thereby facilitating the interfacial Na+ dynamics at low temperature. Furthermore, it effectively blocks the unfavorable side reactions between active materials and electrolytes, improving the structural stability. Consequently, Na0.7Li0.03Mg0.03Ni0.27Mn0.6Ti0.07O2//Na and hard carbon//Na cells deliver a high capacity retention of 90.8 % after 900 cycles at 1C, a capacity over 310 mAh g−1 under −30 °C, respectively, showing long‐term cycling stability and great rate capability at low temperature.
This work constructs a monolithic and amorphous electrode/electrolyte interphase at low temperature which is thin, stable, and contains more organic components, facilitating fast Na+ kinetics, enabling sodium‐ion batteries to achieve long‐term cycling performance and great rate capability at −30 °C.
In this work, we demonstrate a novel cascaded fiber-optic structure depending on Fabry-Perot interference and anti-resonance (AR) effect for seawater salinity and temperature simultaneous ...measurement. An in-fiber microchannel Fabry-Perot interferometer (FPI) is obtained in a single-mode fiber (SMF) by using femtosecond laser radiation and hydrofluoric acid corrosion, which is filled with thermosensitive polymer and able to measure the temperature. A section of hollow-core fiber (HCF) is fused between the SMFs with the square micro-slots ablated on the ends, and the liquid can easily flow into the HCF. To our knowledge, this is the first time that the capillary-type HCF was used as a microfluidic device to measure seawater salinity. Through model analysis and experimental tests, it is confirmed that the proposed sensor can simultaneously measure the salinity and temperature, the corresponding minimum detectable resolutions reach 0.0008‰ and 0.001 ℃, respectively. The performance tests show that the sensor has accurate measurement results, good stability, and repeatability. Besides, the proposed HCF-based internal liquid analysis structure is a promising approach for highly reliable and ultrasensitive biochemical sensing.
•Processing microchannel in single-mode fiber and filling with UV glue to form the Fabry-Perot interferometer.•The anti-resonance structure based on capillary-type hollow-core fiber is demonstrated as a microfluidic device.•The cascaded sensor realizes simultaneous seawater salinity and temperature sensing with the minimum measurement resolutions of 0.0008‰ and 0.001 ℃, respectively.
•An optical salinity quantum sensor based on tapered hetero-core structure is proposed.•Single photons as an input source are used for exciting surface plasmon polaritons.•Though defects are existed, ...the errors bars are beyond the standard quantum limit.•The salinity sensitivity of this proposed sensor is 0.02204/‰ and the resolution is 0.0016‰.•The resolution is one order of magnitude higher than the traditional fiber SPR sensor.
An ultra-resolution optical salinity quantum sensor depended on the tapered hetero-core structure coated with a gold film (around 50 nm) is proposed and demonstrated in this paper. Single photons which work as an input source are used for exciting surface plasmon polaritons at the interface between the metal and the seawater. We exploit the statistical analysis method to get the transmission spectroscopy and quantify its estimation error. Experiment results show that the detected estimation errors of the proposed quantum sensor are completely in agreement with the quantum theory. Though various external interference and experimental defects exist, the error bars are beyond the standard quantum limit. The salinity sensitivity of this proposed sensor is about 0.02204/‰. The resolution of this proposed sensor is 0.0016‰, which is one order of magnitude higher than that of traditional optical fiber surface plasmon resonance (SPR) sensors. The resolution and the sensitivity of the quantum sensor can be further enhanced by modifying the metal coating and the structural parameters. This work realizes the combination of optical fiber sensing technology and quantum plasmonic technology, which will pave the way for the development of high-resolution and high-sensitivity sensor.
•An enhanced taper-based quantum biosensor based on surface plasmon polaritons is demonstrated.•The sensor was with gold coating that operates below the standard quantum limit.•BSA concentration can ...be measured according to the change of transmitted photons.•Detection limit of the proposed biosensor is 0.971 μg/mL.
An enhanced taper-based quantum biosensor based on surface plasmon polaritons (SPPs) with gold coating that operates below the standard quantum limit (SQL) is demonstrated. The sensing structure in this work is fabricated from two Multi-mode fibers (MMFs) and a section of Single-mode fiber (SMF). The gold coating with thickness of 50 nm is prepared by applying the plasma-sputtering apparatus. When the concentration of the bovine serum albumin (BSA) around the proposed quantum biosensor is changed, the number of transmitted photons also changes. Therefore, the BSA concentration can be measured according to the change of transmitted photons. Experiment results show that the obtained sensitivity of the enhanced taper-based quantum biosensor is calculated to be 0.0342/(mg/mL) with the fast response time of 5 s. And, the detection limit (DL) of the proposed biosensor is 0.971 μg/mL, which is one order of magnitude higher than that of the traditional surface plasmon resonance (SPR) probe. The twelve orders of magnitude reduction in intensity afforded by our biosensor should allow a commensurate reduce for equivalent photodamage. The detected estimation errors obtained from the experiment are beyond the SQL and they are very consistent with the quantum theory. Our work in this paper verified that the proposed quantum biosensor can realize the label-free measurement of protein molecules, which provides a new idea for biological engineering, disease detection and single molecule label-free detection.
Bloom syndrome protein (BLM) is a conserved RecQ family helicase involved in the maintenance of genome stability. BLM has been widely recognized as a genome “caretaker” that processes structured DNA. ...In contrast, our knowledge of how BLM behaves on single‐stranded (ss) DNA is still limited. Here, we demonstrate that BLM possesses the intrinsic ability for phase separation and can co‐phase separate with ssDNA to form dynamically arrested protein/ssDNA co‐condensates. The introduction of ATP potentiates the capability of BLM to condense on ssDNA, which further promotes the compression of ssDNA against a resistive force of up to 60 piconewtons. Moreover, BLM is also capable of condensing replication protein A (RPA)‐ or RAD51‐coated ssDNA, before which it generates naked ssDNA by dismantling these ssDNA‐binding proteins. Overall, our findings identify an unexpected characteristic of a DNA helicase and provide a new angle of protein/ssDNA co‐condensation for understanding the genomic instability caused by BLM overexpression under diseased conditions.
Single‐molecule optical‐tweezers analysis revealed that Bloom syndrome helicase can undergo phase separation and form condensates on single‐stranded (ss) DNA, giving rise to the compression and condensation of ssDNA into the condensates that are stable in the presence of a high resistant force.
A low-loss all-straight optical fiber vector magnetic field sensor (OFVMS) based on magnetic fluid (MF) is designed and proposed. The sensing structure is composed of a Section of the C-type optical ...fiber (CTF) embedded in a pair of multi-mode optical fibers (MMF) and wrapped in a capillary with MF. The asymmetry of the CTF provides support for the vector magnetic field measurement whose direction is perpendicular to the optical transmission direction. According to the results of experiments, it can be obtained that the refractive index (RI) sensitivity of the sensing structure is as high as −15716.6072 nm/RIU. In addition, the intensity sensitivity of the OFVMS in the calibrated 90° direction can reach 202.23 pm/G between 0 and 123 G. At the same time, the transmission loss of the proposed sensor structure is not increased by the filling of MF. The sensor demonstrated has dominance in low cost, easy manufacture, and lower loss compared with the same type of sensor device, which has application prospects in vector magnetic field sensing.
Limited evidence revealed conflicting results on relationship between phthalate exposure and clinical pregnancy loss (gestational weeks >6). A prospective cohort study in Chinese pregnant women (n = ...3220) was conducted to investigate the association between urinary phthalate metabolites and clinical pregnancy loss (gestational weeks 6 to 27; n = 109). Morning urine samples during gestational weeks 5 to 14 (mean 10.42) were collected to measure monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). The concentrations of low- and high-molecular weight phthalate metabolites (ΣLMWP <250 Da and ΣHMWP >250 Da) were calculated. Adjusted logistic regression models showed increased risks of clinical pregnancy loss in women with higher creatinine- normalized concentrations of MEP, MBP, MEOHP, MEHHP, ΣLMWP and ΣHMWP. Stratified analysis by gestational weeks (10 weeks) of miscarriage indicated positive associations of MEP, MEOHP, MEHHP and ΣHMWP with embryonic loss (during gestational weeks 6 to 10). The only association of foetal loss (during gestational weeks 11 to 27) was observed with MEHHP. Our findings suggested that Chinese women who were exposed to phthalates during early pregnancy had an increased risk of clinical pregnancy loss, especially embryonic loss.
Biliary complication (BC) is still regarded as the Achilles’ heel of a living donor liver transplantation (LDLT). This study aims to evaluate the longterm outcomes of the duct‐to‐duct (DD) biliary ...reconstruction using 7‐0 suture and to identify the risk factors of BCs after LDLTs. Data of 140 LDLTs between 2006 and 2015 were analyzed. All biliary reconstructions were performed as DD anastomoses using 7‐0 suture: 102 for the right lobe, 20 for the left lobe, and 18 for right posterior sector grafts. BC was defined as a bile leakage (BL) or a biliary stricture (BS), and the median follow‐up time after LDLT was 65 months. A total of 19 recipients (13.5%) developed BCs (8 BLs and 16 BSs) after LDLT. The survival rates between recipients with and without BCs were 83% and 86.7%, respectively (P = 0.88). In univariate analyses, the risk factors for BC were small diameter of the graft’s bile duct, long warm ischemic time, small graft‐to‐recipient weight ratio, and no use of external biliary stent (EBS). The graft’s bile duct diameter ≤ 3 mm and no use of EBS were determined as independent risk factors (hazard ratios of 9.74 and 7.68, respectively) in multivariate analyses. The 116 recipients with EBS had no BL, 11 had BSs (9%), while 24 without EBS had 8 BLs (33%) and 5 BSs (21%). After a propensity score match between the recipients with and without EBS, the EBS group (24) developed only 1 BS (4%). In conclusion, DD anastomosis using 7‐0 suture combined with EBS could provide favorable longterm outcomes after LDLT, which should thus be considered the surgical technique of choice for LDLTs.
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