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1.
Anal Chim Acta ; 1316: 342820, 2024 Aug 08.
Article in English | MEDLINE | ID: mdl-38969422

ABSTRACT

This research presents an innovative reflective fiber optic probe structure, mutinously designed to detect H7N9 avian influenza virus gene precisely. This innovative structure skillfully combines multimode fiber (MMF) with a thin-diameter seven-core photonic crystal fiber (SCF-PCF), forming a semi-open Fabry-Pérot (FPI) cavity. This structure has demonstrated exceptional sensitivity in light intensity-refractive index (RI) response through rigorous theoretical and experimental validation. The development of a quasi-distributed parallel sensor array, which provides temperature compensation during measurements, has achieved a remarkable RI response sensitivity of up to 532.7 dB/RIU. The probe-type fiber optic sensitive unit, expertly functionalized with streptavidin, offers high specificity in detecting H7N9 avian influenza virus gene, with an impressively low detection limit of 10-2 pM. The development of this biosensor marks a significant development in biological detection, offering a practical engineering solution for achieving high sensitivity and specificity in light-intensity-modulated biosensing. Its potential for wide-ranging applications in various fields is now well-established.


Subject(s)
Biosensing Techniques , Influenza A Virus, H7N9 Subtype , Temperature , Biosensing Techniques/methods , Influenza A Virus, H7N9 Subtype/genetics , Influenza A Virus, H7N9 Subtype/isolation & purification , Optical Fibers , Limit of Detection , Fiber Optic Technology/methods , Animals , Genes, Viral
2.
eNeuro ; 11(7)2024 Jul.
Article in English | MEDLINE | ID: mdl-39025674

ABSTRACT

Quantifying and analyzing licking behavior can offer valuable insights into fundamental neurobiological mechanisms controlling animal consummatory behaviors. Lickometers are typically based on electrical properties, a strategy that comes with limitations, including susceptibility to electrical interference and generation of electrical disturbances in electrophysiological measurements. While optical lickometers offer an alternative method to measure licks and quantify fluid intake in animals, they are prone to false readings and susceptibility to outside light sources. To overcome this problem, we propose a low-cost open-source lickometer that combines a restricted infrared beam defined by optical fibers, with a poke design that allows easy access to the tongue while limiting access of other body parts and external light sources. This device also includes features for detecting nose pokes and presenting visual cues during behavioral tasks. We provide validation experiments that demonstrate the optical lickometer's reliability, high-sensitivity and precision, and its application in a behavioral task, showcasing the potential of this tool to study lick microstructure in combination with other techniques, such as imaging of neural activity, in freely moving mice.


Subject(s)
Optical Fibers , Animals , Mice , Drinking Behavior/physiology , Mice, Inbred C57BL , Male , Reproducibility of Results , Equipment Design , Fiber Optic Technology/methods , Fiber Optic Technology/instrumentation
3.
STAR Protoc ; 5(2): 103131, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38875116

ABSTRACT

To exclude the influence of motion on in vivo calcium imaging, animals usually need to be fixed. However, the whole-body restraint can cause stress in animals, affecting experimental results. In addition, some brain regions are prone to bleeding during surgery, which lowers the success rate of calcium imaging. Here, we present a protocol for calcium imaging using heparin-treated fiber in head-fixed mice. We describe steps for stereotaxic surgery, including virus injection and optic fiber implantation, fiber photometry, and data analysis. For complete details on the use and execution of this protocol, please refer to Du et al.1.


Subject(s)
Brain , Photometry , Animals , Mice , Photometry/methods , Brain/diagnostic imaging , Optical Fibers , Calcium/metabolism , Calcium/analysis , Stereotaxic Techniques , Fiber Optic Technology/methods
4.
ACS Sens ; 9(6): 3027-3036, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38864606

ABSTRACT

Surface plasmon (SP) excitation in metal-coated tilted fiber Bragg gratings (TFBGs) has been a focal point for highly sensitive surface biosensing. Previous efforts focused on uniform metal layer deposition around the TFBG cross section and temperature self-compensation with the Bragg mode, requiring both careful control of the core-guided light polarization and interrogation over most of the C + L bands. To circumvent these two important practical limitations, we studied and developed an original platform based on partially coated TFBGs. The partial metal layer enables the generation of dual-comb resonances, encompassing highly sensitive (TM/EH mode families) and highly insensitive (TE/HE mode families) components in unpolarized transmission spectra. The interleaved comb of insensitive modes acts as wavelength and power references within the same spectral region as the SP-active modes. Despite reduced fabrication and measurement complexity, refractometric accuracy is not compromised through statistical averaging over seven individual resonances within a narrowband window of 10 nm. Consequently, measuring spectra over 60 nm is no longer needed to compensate for small temperature or power fluctuations. This sensing platform brings the following important practical assets: (1) a simpler fabrication process, (2) no need for polarization control, (3) limited bandwidth interrogation, and (4) maintained refractometric accuracy, which makes it a true game changer in the ever-growing plasmonic sensing domain.


Subject(s)
Optical Fibers , Surface Plasmon Resonance , Surface Plasmon Resonance/instrumentation , Surface Plasmon Resonance/methods , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Fiber Optic Technology/instrumentation
5.
Biosens Bioelectron ; 261: 116521, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38917514

ABSTRACT

Oceanic facilities and equipment corrosion present considerable economic and safety concerns, predominantly due to microbial corrosion. Early detection of corrosive microbes is pivotal for effective monitoring and prevention. Yet, traditional detection methods often lack specificity, require extensive processing time, and yield inaccurate results. Hence, the need for an efficient real-time corrosive microbe monitoring technology is evident. Pseudomonas aeruginosa, a widely distributed microorganism in aquatic environments, utilizes its production of quinone-like compounds, specifically pyocyanin (PYO), to corrode metals. Here, we report a novel fiber optic surface plasmon resonance (SPR) sensor modified by the C-terminal of BrlR protein (BrlR-C), which is a specific receptor of PYO molecule, to detect P. aeruginosa in aquatic environments. The results showed that the sensor had a good ability to recognize PYO in the concentration range of 0-1 µg/mL, and showed excellent sensing performance in real-time monitoring the growth status of P. aeruginosa. With a strong selectivity of PYO, the sensor could clearly detect P. aeruginosa against other bacteria in seawater environment, and exhibited excellent anti-interference ability against variations in pH, temperature and pressure and other interfering substances. This study provides a useful tool for monitoring corrosive P. aeruginosa biofilm in aquatic environments, which is a first of its kind example that serves as a laboratory model for the application of fiber optic technology in real-world scenarios to monitoring biofilms in microbial corrosion and biofouling.


Subject(s)
Biofilms , Biosensing Techniques , Fiber Optic Technology , Pseudomonas aeruginosa , Pyocyanine , Surface Plasmon Resonance , Pseudomonas aeruginosa/isolation & purification , Surface Plasmon Resonance/methods , Pyocyanine/analysis , Pyocyanine/chemistry , Biosensing Techniques/methods , Corrosion , Optical Fibers , Seawater/microbiology , Seawater/chemistry , Equipment Design
6.
ACS Sens ; 9(6): 3413-3422, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38887933

ABSTRACT

In recent years, wearable devices have been widely used for human health monitoring. Such monitoring predominantly relies on the principles of optics and electronics. However, electronic detection is susceptible to electromagnetic interference, and traditional optical fiber detection is limited in functionality and unable to simultaneously detect both physical and chemical signals. Hence, a wearable, embedded asymmetric color-blocked optical fiber sensor based on a hydrogel has been developed. Its sensing principle is grounded in the total internal reflection within the optical fiber. The method for posture sensing involves changes in the light path due to fiber bending with color blocks providing wavelength-selective modulation by absorption changes. Sweat pH sensing is facilitated by variations in fluorescence intensity triggered by sweat-induced conformational changes in Rhodamine B. With just one fiber, it achieves both physical and chemical signal detection. Fabricated using a molding technique, this fiber boasts excellent biocompatibility and can accurately discern single and multiple bending points, with a recognition range of 0-90° for a single segment, a detection limit of 0.02 mm-1 and a sweat pH sensing linear regression R2 of 0.993, alongside great light propagation properties (-0.6 dB·cm-1). With its extensive capabilities, it holds promise for applications in medical monitoring.


Subject(s)
Hydrogels , Optical Fibers , Posture , Sweat , Wearable Electronic Devices , Hydrogen-Ion Concentration , Sweat/chemistry , Humans , Hydrogels/chemistry , Posture/physiology , Rhodamines/chemistry , Biosensing Techniques/methods , Monitoring, Physiologic/methods , Monitoring, Physiologic/instrumentation
7.
Food Chem ; 455: 139773, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-38833856

ABSTRACT

A molecularly imprinted polymer (MIP) based microfiber differential demodulation sensing system for sodium benzoate (SB) concentration detection is proposed. The specific binding of MIP on the surface of microfibers with SB can lead to changes in local refractive index (RI). RI change induces a drift in the interference wavelength, which can be monitored by the power difference between two fiber Bragg gratings (FBGs). The sensing system can detect SB in the concentration range of 0.1-50 µg/ml, and interference wavelength and FBG power difference sensitivities are 0.55 nm/(µg/ml) and 2.64 dB/(µg/ml) in the low concentration range of 0.1-1 µg/ml, respectively, with a limit of detection (LOD) of 0.1 µg/ml. This microfiber differential demodulation sensing system is not only simple to fabricate, but also simplifies the demodulation equipment to reduce the cost, which providing a simple, reliable and low-cost technique for the quantitative detection of SB concentration in beverages and flavoured foods.


Subject(s)
Molecularly Imprinted Polymers , Sodium Benzoate , Sodium Benzoate/analysis , Sodium Benzoate/chemistry , Molecularly Imprinted Polymers/chemistry , Optical Fibers , Limit of Detection , Food Contamination/analysis , Molecular Imprinting , Polymers/chemistry
8.
Lasers Surg Med ; 56(6): 597-605, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38923545

ABSTRACT

OBJECTIVES: A fast, simple, versatile, and reliable method to record light emission intensity profiles of cylindrical light diffusers (CDFs) in air and transparent liquids has been developed. METHODS: A fluorescent color glass filter (RG695) converts red light emitted by a cylindrical diffuser fiber into near-infrared light in an emission angle-independent manner. The red light was provided from a diode laser system at 635 nm. Near-infrared fluorescence from the RG695 was imaged with a camera. Images from this camera were processed to obtain emission intensity profiles. Cylindrical diffuser fiber profiles of four different manufacturers were compared. RESULTS: The proposed method provides angle-independent intensity profiles of cylindrical diffuser fibers with a single camera shot. It could be demonstrated that dependent on the underlying principle of how the diffuser fiber tips emit light, the emission profile can change significantly in media with different refractive indices. CONCLUSIONS: By converting the light emitted by a diffuser fiber tip into fluorescence light one can eliminate the dependence of the recorded profile on the emission angle from the diffusor. This approach allows for easily taking into account refraction-index (mis)matching by placing the equipment into a suitable liquid. The proposed measurement principle bears potential for quality assurance measurements of CDFs used for interstitial laser thermotherapy or photodynamic therapy.


Subject(s)
Equipment Design , Lasers, Semiconductor/therapeutic use , Fluorescence , Optical Fibers , Fiber Optic Technology/instrumentation
9.
Sci Rep ; 14(1): 13117, 2024 06 07.
Article in English | MEDLINE | ID: mdl-38849511

ABSTRACT

A surface plasmon resonance (SPR) phenomenon implemented via D-shaped polymer optical fiber (POF) is exploited to realize cortisol biosensors. In this work, two immonosensors are designed and developed for the qualitative as well as quantitative measurement of cortisol in artificial and real samples. The performances of the POF-based biosensors in cortisol recognition are achieved using different functionalization protocols to make the same antibody receptor layer over the SPR surface via cysteamine and lipoic acid, achieving a limit of detection (LOD) of 0.8 pg/mL and 0.2 pg/mL, respectively. More specifically, the use of cysteamine or lipoic acid changes the distance between the receptor layer and the SPR surface, improving the sensitivity at low concentrations of about one order of magnitude in the configuration based on lipoic acid. The LODs of both cortisol biosensors are achieved well competitively with other sensor systems but without the need for amplification or sample treatments. In order to obtain the selectivity tests, cholesterol and testosterone were used as interfering substances. Moreover, tests in simulated seawater were performed for the same cortisol concentration range achieved in buffer solution to assess the immunosensor response to the complex matrix. Finally, the developed cortisol biosensor was used in a real seawater sample to estimate the cortisol concentration value. The gold standard method has confirmed the estimated cortisol concentration value in real seawater samples. Liquid-liquid extraction was implemented to maximize the response of cortisol in liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis.


Subject(s)
Aquaculture , Biosensing Techniques , Hydrocortisone , Seawater , Surface Plasmon Resonance , Hydrocortisone/analysis , Seawater/analysis , Biosensing Techniques/methods , Surface Plasmon Resonance/methods , Aquaculture/methods , Limit of Detection , Optical Fibers , Polymers/chemistry
10.
Opt Express ; 32(10): 17239-17254, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38858913

ABSTRACT

Doxorubicin (DOX) is an important drug for cancer treatment, but its clinical application is limited due to its toxicity and side effects. Therefore, detecting the concentration of DOX during treatment is crucial for enhancing efficacy and reducing side effects. In this study, the authors developed a biophotonic fiber sensor based on localized surface plasmon resonance (LSPR) with the multimode fiber (MMF)-four core fiber (FCF)-seven core fiber (SCF)-MMF-based direct-taper and anti-taper structures for the specific detection of DOX. Compared to other detection methods, it has the advantages of high sensitivity, low cost, and strong anti-interference ability. In this experiment, multi-walled carbon nanotubes (MWCNTs), cerium-oxide nanorods (CeO2-NRs), and gold nanoparticles (AuNPs) were immobilized on the probe surface to enhance the sensor's biocompatibility. MWCNTs and CeO2-NRs provided more binding sites for the fixation of AuNPs. By immobilizing AuNPs on the surface, the LSPR was stimulated by the evanescent field to detect DOX. The sensor surface was functionalized with DOX aptamers for specific detection, enhancing its specificity. The experiments demonstrated that within a linear detection range of 0-10 µM, the sensitivity of the sensor is 0.77 nm/µM, and the limit of detection (LoD) is 0.42 µM. Additionally, the probe's repeatability, reproducibility, stability, and selectivity were evaluated, indicating that the probe has high potential for detecting DOX during cancer treatment.


Subject(s)
Doxorubicin , Gold , Metal Nanoparticles , Surface Plasmon Resonance , Doxorubicin/pharmacology , Humans , Surface Plasmon Resonance/instrumentation , Gold/chemistry , Metal Nanoparticles/chemistry , Neoplasms/drug therapy , Nanotubes, Carbon/chemistry , Biosensing Techniques/instrumentation , Optical Fibers , Equipment Design , Antibiotics, Antineoplastic/analysis , Cerium/chemistry , Fiber Optic Technology/instrumentation
11.
Opt Express ; 32(11): 20024-20034, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38859121

ABSTRACT

An optical fiber sensing probe using a composite sensitive film of polyacrylonitrile (PAN) nanofiber membrane and gold nanomembrane is presented for the detection of a carcinoembryonic antigen (CEA), a biomarker associated with colorectal cancer and other diseases. The probe is based on a tilted fiber Bragg grating (TFBG) with a surface plasmon resonance (SPR) gold nanomembrane and a functionalized polyacrylonitrile (PAN) PAN nanofiber coating that selectively binds to CEA molecules. The performance of the probe is evaluated by measuring the spectral shift of the TFBG resonances as a function of CEA concentration in buffer. The probe exhibits a sensitivity of 0.46 dB/(µg/ml), a low limit of detection of 505.4 ng/mL in buffer, and a good selectivity and reproducibility. The proposed probe offers a simple, cost-effective, and a novel method for CEA detection that can be potentially applied for clinical diagnosis and monitoring of CEA-related diseases.


Subject(s)
Acrylic Resins , Carcinoembryonic Antigen , Gold , Nanofibers , Optical Fibers , Surface Plasmon Resonance , Carcinoembryonic Antigen/analysis , Gold/chemistry , Nanofibers/chemistry , Surface Plasmon Resonance/instrumentation , Surface Plasmon Resonance/methods , Acrylic Resins/chemistry , Humans , Biosensing Techniques/instrumentation , Membranes, Artificial , Metal Nanoparticles/chemistry , Reproducibility of Results , Fiber Optic Technology/instrumentation
12.
Sensors (Basel) ; 24(11)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38894393

ABSTRACT

As the global aging population increases, the demand for rehabilitation of elderly hand conditions has attracted increased attention in the field of wearable sensors. Owing to their distinctive anti-electromagnetic interference properties, high sensitivity, and excellent biocompatibility, optical fiber sensors exhibit substantial potential for applications in monitoring finger movements, physiological parameters, and tactile responses during rehabilitation. This review provides a brief introduction to the principles and technologies of various fiber sensors, including the Fiber Bragg Grating sensor, self-luminescent stretchable optical fiber sensor, and optic fiber Fabry-Perot sensor. In addition, specific applications are discussed within the rehabilitation field. Furthermore, challenges inherent to current optical fiber sensing technology, such as enhancing the sensitivity and flexibility of the sensors, reducing their cost, and refining system integration, are also addressed. Due to technological developments and greater efforts by researchers, it is likely that wearable optical fiber sensors will become commercially available and extensively utilized for rehabilitation.


Subject(s)
Optical Fibers , Wearable Electronic Devices , Humans , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/methods , Fiber Optic Technology/instrumentation , Rehabilitation/instrumentation , Biosensing Techniques/instrumentation , Biosensing Techniques/methods
13.
ACS Appl Mater Interfaces ; 16(25): 32662-32678, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38863342

ABSTRACT

The pervasive global issue of population aging has led to a growing demand for health monitoring, while the advent of electronic wearable devices has greatly alleviated the strain on the industry. However, these devices come with inherent limitations, such as electromagnetic radiation, complex structures, and high prices. Herein, a Solaris silicone rubber-integrated PMMA polymer optical fiber (S-POF) intelligent insole sensing system has been developed for remote, portable, cost-effective, and real-time gait monitoring. The system is capable of sensitively converting the pressure of key points on the sole into changes in light intensity with correlation coefficients of 0.995, 0.952, and 0.910. The S-POF sensing structure demonstrates excellent durability with a 4.8% variation in output after 10,000 cycles and provides stable feedback for bending angles. It also exhibits water resistance and temperature resistance within a certain range. Its multichannel multiplexing framework allows a smartphone to monitor multiple S-POF channels simultaneously, meeting the requirements of convenience for daily care. Also, the system can efficiently and accurately provide parameters such as pressure, step cadence, and pressure distribution, enabling the analysis of gait phases and patterns with errors of only 4.16% and 6.25% for the stance phase (STP) and the swing phase (SWP), respectively. Likewise, after comparing various AI models, an S-POF channel-based gait pattern recognition technique has been proposed with a high accuracy of up to 96.87%. Such experimental results demonstrate that the system is promising to further promote the development of rehabilitation and healthcare.


Subject(s)
Wearable Electronic Devices , Humans , Gait/physiology , Smartphone , Artificial Intelligence , Shoes , Optical Fibers
14.
PeerJ ; 12: e17570, 2024.
Article in English | MEDLINE | ID: mdl-38903879

ABSTRACT

Objectives: This study sought to evaluate the diagnostic value of a non-contact optical fiber mattress for apnea and hypopnea and compare it with traditional polysomnography (PSG) in adult obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: To determine the value of a non-contact optical fiber mattress for apnea and hypopnea, six healthy people and six OSAHS patients were selected from Tongji Hospital to design a program to identify apnea or hypopnea. A total of 108 patients who received polysomnography for drowsiness, snoring or other suspected OSAHS symptoms. All 108 patients were monitored with both the non-contact optical fiber mattress and PSG were collected. Results: Six healthy controls and six patients with OSAHS were included. The mean apnea of the six healthy controls was 1.22 times/h, and the mean hypopnea of the six healthy controls was 2 times/h. Of the six patients with OSAHS, the mean apnea was 12.63 times/h, and the mean hypopnea was 19.25 times/h. The non-contact optical fiber mattress results showed that the mean apnea of the control group was 3.17 times/h and the mean hypopnea of the control group was 3.83 times/h, while the mean apnea of the OSAHS group was 11.95 times/h and the mean hypopnea of the OSAHS group was 17.77 times/h. The apnea index of the non-contact optical fiber mattress was positively correlated with the apnea index of the PSG (P < 0.05, r = 0.835), and the hypopnea index of the non-contact optical fiber mattress was also positively correlated with the hypopnea index of the PSG (P < 0.05, r = 0.959). The non-contact optical fiber mattress had high accuracy (area under curve, AUC = 0.889), specificity (83.4%) and sensitivity (83.3%) for the diagnosis of apnea. The non-contact fiber-optic mattress also had high accuracy (AUC = 0.944), specificity (83.4%) and sensitivity (100%) for the diagnosis of hypopnea. Among the 108 patients enrolled, there was no significant difference between the non-contact optical fiber mattress and the polysomnography monitor in total recording time, apnea hypopnea index (AHI), average heart rate, tachycardia index, bradycardia index, longest time of apnea, average time of apnea, longest time of hypopnea, average time of hypopnea, percentage of total apnea time in total sleep time and percentage of total hypopnea time in total sleep time. The AHI value of the non-contact optical fiber mattress was positively correlated with the AHI value of the PSG (P < 0.05, r = 0.713). The specificity and sensitivity of the non-contact optical fiber mattress AHI in the diagnosis of OSAHS were 95% and 93%, with a high OSAHS diagnostic accuracy (AUC = 0.984). Conclusion: The efficacy of the non-contact optical fiber mattress for OSAHS monitoring was not significantly different than PSG monitoring. The specificity of the non-contact optical mattress for diagnosing OSAHS was 95% and its sensitivity was 93%, with a high OSAHS diagnostic accuracy.


Subject(s)
Optical Fibers , Polysomnography , Sleep Apnea, Obstructive , Humans , Sleep Apnea, Obstructive/diagnosis , Male , Polysomnography/instrumentation , Polysomnography/methods , Female , Middle Aged , Retrospective Studies , Adult , Beds , Sensitivity and Specificity , Case-Control Studies , Aged
15.
J Biophotonics ; 17(7): e202400083, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38695386

ABSTRACT

One of the diagnostic tool for clinical evaluation and disease diagnosis is a pulse waveform analysis. High fidelity radial artery pulse waveforms have been investigated in clinical research to compute central aortic pressure, which has been demonstrated to be predictive of cardiovascular diseases. The radial artery must be inspected from several angles in order to obtain the best pulse waveform for estimate and diagnosis. In this study, we present the design and experimental testing of an optical sensor based on Fiber Bragg Gratings (FBG). A 3D printed device along with the FBG is used to measure the radial artery pulses. The proposed sensor is used for the purpose of quantifying the radial artery pulse waveform across major pulse position point. The suggested optical sensing system can measure the pulse signal with good accuracy. The main characteristic parameters of the pulse can then be retrieved from the processed signal for their use in clinical applications. By conducting experiments under the direction of medical experts, the pulse signals are measured. In order to experimentally validate the sensor, we used it to detect the pulse waveforms at Guan position of the wrist's radial artery in accordance with the diagnostic standards. The findings show that combining optical technologies for physiological monitoring and radial artery pulse waveform monitoring using FBG in clinical applications are highly feasible.


Subject(s)
Radial Artery , Radial Artery/physiology , Humans , Blood Pressure , Optical Fibers , Equipment Design , Optical Phenomena , Blood Pressure Determination/instrumentation , Blood Pressure Determination/methods , Optical Devices
16.
Talanta ; 277: 126317, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38810383

ABSTRACT

In this study, we present a novel biomarker detection platform employing a modified S-tapered fiber coated with gold nanoparticle/graphene oxide (GNP/GO) for quantifying human epidermal growth factor receptor-2 (HER2) concentrations, using antibodies as sensing elements. The fabrication of this device involves implementing an in-situ layer-by-layer technique coupled with a chemical adsorption step to achieve the self-assembly of GNP, GO, and antibodies on the STF surface. The detection mechanism relies on monitoring the refractive index changes induced by the adsorption of HER2 onto the immobilized antibodies. For comparative analysis, both monoclonal antibody (mAb) and the novel nanobody (Nb) were employed in constructing the STF immunosensor, referred to as the mAb immunosensor and Nb immunosensor, respectively. Spectral analysis results highlight that the Nb immunosensor exhibits twice the sensitivity of the mAb immunosensor. This enhanced sensitivity is attributed to the small size, high antigen affinity, strong specificity, and structural stability of Nb. The Nb immunosensor demonstrated an impressive detection limit of 0.001 nM for HER2, surpassing the detection limit of the mAb immunosensor. These findings underscore the potential of the proposed Nb immunosensor as a promising and sensitive tool for HER2 detection, contributing to the diagnosis and prognosis of breast cancer. Furthermore, the simplicity of production and excellent optical performance position the Nb immunosensor as a prospective real-time biosensor with minimal cytotoxicity.


Subject(s)
Biosensing Techniques , Gold , Graphite , Metal Nanoparticles , Optical Fibers , Receptor, ErbB-2 , Single-Domain Antibodies , Receptor, ErbB-2/immunology , Receptor, ErbB-2/analysis , Humans , Biosensing Techniques/methods , Immunoassay/methods , Single-Domain Antibodies/immunology , Single-Domain Antibodies/chemistry , Graphite/chemistry , Metal Nanoparticles/chemistry , Gold/chemistry , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/chemistry , Antibodies, Immobilized/immunology , Antibodies, Immobilized/chemistry , Limit of Detection
17.
Anal Chim Acta ; 1309: 342665, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38772653

ABSTRACT

BACKGROUND: The concentration of cytochrome C is demonstrated to be an effective indicator of the microbial corrosion strength of metals. Traditional cytochrome C sensor can detect cytochrome C with a low detection limit, but their use is limited by their high cost, cumbersome operation, and susceptibility to malignant environments. In addition, studies on the monitoring of cytochrome C in the field of microbial corrosion has still not been carried out. Therefore, there is a need for a highly sensitive, selective, low-cost, anti-interference, and stable cytochrome C sensor with online monitoring and remote sensing capabilities for in-situ measurement of microbial corrosion strength. RESULTS: This paper proposed a highly sensitive label-free fiber-optic sensor based on Mach-Zehnder interferometer (MZI) for in-situ measurement of the microbial corrosion marker cytochrome C. Two-dimensional Ti2C-MXene material is uniformly immobilized onto the surface of the sensing area to improve the sensitivity, hydrophilicity, and specific surface area of the sensing area, as well as to facilitate the immobilization of specific sensitive materials. The cytochrome C antibody is modified on the surface of Ti2C-MXene to specifically recognize cytochrome C, whose concentration variation can be measured by monitoring the spectral shift of MZI sensor. Results demonstrate a measurement sensitivity of 1.428 nm/µM for cytochrome C concentrations ranging from 0 to 7.04 µM. The detection limit of the sensor is calculated to be 0.392 µM with remarkable performance, including selectivity, stability, and reliability. Besides, the measurement result of the proposed sensor in real microbial corrosive environment is consistent with that of the ideal environment. SIGNIFICANCE AND NOVELTY: This is the first instance of achieving in-situ and label-free measurement of cytochrome C by using a fiber-optic MZI sensor, which undoubtedly provides a feasible solution for the effective monitoring of microbial metal corrosion in the environment.


Subject(s)
Cytochromes c , Fiber Optic Technology , Interferometry , Titanium , Cytochromes c/analysis , Cytochromes c/metabolism , Titanium/chemistry , Biosensing Techniques/methods , Limit of Detection , Optical Fibers , Corrosion
18.
Sensors (Basel) ; 24(9)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38732777

ABSTRACT

Optical fiber sensors are extensively employed for their unique merits, such as small size, being lightweight, and having strong robustness to electronic interference. The above-mentioned sensors apply to more applications, especially the detection and monitoring of vital signs in medical or clinical. However, it is inconvenient for daily long-term human vital sign monitoring with conventional monitoring methods under the uncomfortable feelings generated since the skin and devices come into direct contact. This study introduces a non-invasive surveillance system that employs an optical fiber sensor and advanced deep-learning methodologies for precise vital sign readings. This system integrates a monitor based on the MZI (Mach-Zehnder interferometer) with LSTM networks, surpassing conventional approaches and providing potential uses in medical diagnostics. This could be potentially utilized in non-invasive health surveillance, evaluation, and intelligent health care.


Subject(s)
Deep Learning , Optical Fibers , Vital Signs , Humans , Vital Signs/physiology , Monitoring, Physiologic/methods , Monitoring, Physiologic/instrumentation , Neural Networks, Computer
19.
Int J Mol Sci ; 25(10)2024 May 17.
Article in English | MEDLINE | ID: mdl-38791532

ABSTRACT

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions. It was established that a fluorinated cardo copolyimide (FCPI) based on 2,2-bis-(3,4-dicarboxydiphenyl)hexafluoropropane dianhydride, 9,9-bis-(4-aminophenyl)fluorene and 2,2-bis-(4-aminophenyl)hexafluoropropane (1.00:0.75:0.25 mol) has excellent solubility in di(met)acrylates. This made it possible to prepare solutions of FCPI in such monomers, to study the effect of FCPI on the kinetics of their photopolymerization in situ and the properties of the resulting polymers. According to the obtained data, the solutions of FCPI (23 wt.%) in 1,4-butanediol diacrylate (BDDA) and FCPI (15 wt.%) in tetraethylene glycol diacrylate were tested for the formation of the primary protective coatings of the silica optical fibers. It was found that the new coating of poly(BDDA-FCPI23%) can withstand prolonged annealing at 200 °C (72 h), which is comparable or superior to the known most thermally stable photo-curable coatings. The proposed approach can be applied to obtain other functional materials.


Subject(s)
Optical Fibers , Polymerization , Silicon Dioxide , Silicon Dioxide/chemistry , Solubility , Imides/chemistry , Temperature , Acrylates/chemistry , Polymers/chemistry , Halogenation , Photochemical Processes
20.
Water Res ; 257: 121682, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38718654

ABSTRACT

Photocatalyst-coated optical fibers (P-OFs) using UV-A LEDs offer a highly promising solution for the degradation of micropollutants within municipal, reuse, industrial or home distribution systems, by integrating P-OFs into water storage tanks. P-OFs have photocatalysts attached to bundles of optical fibers, enabling their direct deployment within tanks. This eliminates the necessity for photocatalyst slurries, which would require additional membrane or separation systems. However, a current limitation of P-OFs is light management, specifically light oversaturation of the coated photocatalysts and short light transmission distances along fibers. This study overcomes this limitation and reveals strategies to improve the light dissipation uniformity along P-OFs, and demonstrates the performance of P-OFs on degrading a model micropollutant, carbamazepine (CBZ). Key tunable variables of fibers and light emission conditions, including photocatalyst coating patchiness (p), minimum light incident angles (θm), radiant flux launched to fibers (Φi), and fiber diameters (D), were modeled to establish their relationships with the light dissipation uniformity in TiO2-coated quartz optical fibers (TiO2-QOFs). We then validated modeling insights by conducting experiments to examine how these variables influence the generation of evanescent waves which are localized energy on fiber surfaces, leading to either photocatalyst activation or the recapture of unused light back into fibers. We observed substantial enhancements in evanescent waves generation by decreasing p and increasing θm, resulting in uniform light dissipation which reduces light oversaturation and improves light transmission distances. Moreover, these optimizations led to a remarkable three-fold improvement in CBZ degradation rates and a 65% reduction in energy consumption. Such improvement substantially reduces the capital and operational cost and enhances practicality of energy-efficient photocatalysis without additional chemical oxidants for micropollutant degradation in water storage tanks.


Subject(s)
Optical Fibers , Quartz , Titanium , Water Pollutants, Chemical , Titanium/chemistry , Quartz/chemistry , Water Pollutants, Chemical/chemistry , Catalysis , Water Purification/methods , Carbamazepine/chemistry
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