Optic Surface Plasmon Resonance Sensor Research Articles

Designing of High-Sensitivity Optical Surface Plasmon Resonance Sensor (OSPRS) for Fast and Accurate Diagnosis of Dengue Virus (DeVs)

Designing of High-Sensitivity Optical Surface Plasmon Resonance Sensor (OSPRS) for Fast and Accurate Diagnosis of Dengue Virus (DeVs)

Dual-parameter fiber optic surface plasmon resonance sensor with narrow FWHM based on an incidence angle adjusting method

We propose a dual-parameter surface plasmon resonance (SPR) sensor based on a simple, and effective incidence angle adjustment method. It is capable of simultaneously detecting the refractive index and temperature of a liquid. For conventional SPR fiber sensors, the resonance dip will be abnormally broadened in the near-infrared band, leading to difficulty in identifying the SPR dip by the spectrometer. The FWHM of the resonance dip depends on the SPR intensity. Therefore, we propose to utilize the bubble structure to change the incidence angle, which can enhance SPR intensity and thus reduce the FWHM of the resonance dip. During our experiments, we investigated the modulation effect of bubble size on the SPR effect. Subsequently, a two-parameter sensor with a narrow FWHM was prepared using PDMS, and the experimental results show that no crosstalk exists between the two sensing channels. This sensor is beneficial for improving the FWHM of SPR dip.

[formula omitted] modified U-shaped fiber surface plasmon resonance sensor with high sensitivity

Design of optical fiber structure and sensitive material coating are two effective performance improvement approaches for fiber optic surface plasmon resonance (SPR) sensors. Here, a tungsten diselenide (WSe2) modified U-shaped fiber optic SPR sensor is proposed. It is found that the sensing performances of the proposed U-shaped probe can be controlled with the thickness of gold film, WSe2 layers, and bending radius of the U-shaped fiber. A sensitivity of 27520 nm/RIU (RIU: refractive index unit) is obtained with the optimized U-shaped probe, which is about 11.56-fold and 12.29-fold improvements over the traditional in-line transmission fiber optic SPR sensors without WSe2 coating and with monolayer WSe2, respectively. These results demonstrate a promising approach for sensitivity improvement of fiber optic SPR sensors, and the proposed WSe2 modified U-shaped fiber optic SPR sensor may have prospective potential applications in biological sensing, chemical sensing, and environmental monitoring.

All Optic-Fiber Waveguide-Coupled SPR Sensor for CRP Sensing Based on Dielectric Layer and Poly-Dopamine

We developed an all optic-fiber waveguide-coupled surface plasmon resonance (SPR) sensor using zirconium disulfide (ZrS2) and poly-dopamine (PDA) as the dielectric layer and biological cross-linker, respectively. This sensor can be employed to monitor the entire process of the C-reactive protein (CRP) sensing, including antibody modification and antigen detection. The design and the optimization of the optical fiber waveguide-coupled SPR sensor were realized, based on the transfer matrix method and first-principles calculations. The sensor was fabricated and characterized according to the optimized parameters. The experimental setup was implemented to measure the entire process of antibody modification and antigen detection for CRP with the detection limit of 3.21 pmol·mL−1, and the specificity tests were also carried out.

Gratings for enhanced sensitivity: advancing D-shaped optical fiber surface plasmon resonance sensors with Ag-Fe2O3 structures

This research delves into enhancing biosensing sensitivity by optimizing D-shaped optical fiber surface plasmon resonance (SPR) sensors employing Ag-Fe2O3 structures. By investigating the influence of different grating structures—rectangular, triangular, and elliptical—on sensor performance, a comprehensive analysis was conducted to ascertain the impact of these structural variations on sensitivity and detection precision. The study revealed that while the rectangular structure exhibited a sensitivity of 6.4 µm/RIU, the triangular structure outperformed with an impressive sensitivity of 7.2 µm/RIU. Moreover, the detection accuracy, quantified by the detection angle (DA), reached 15.7(µm)−1 for the triangular grating, surpassing the rectangular grating’s detection angle of 14.8(µm)−1. These results underscore the crucial role of structural design in enhancing sensor performance, with the triangular grating demonstrating superior sensitivity and detection precision in the context of plasmonic resonance. The extended detection range of refractive indices around 1.39 further expands the sensor’s applicability in diverse chemical and biomedical analyses. Notably, the sensor’s capability to detect various chemical solutions and diseases—including plasma, tuberculosis, white blood cells, and breast cancer cells—underscores its versatility and efficacy in dual-parameter detection. Through meticulous simulations and analysis, this study provides valuable insights into optimizing sensor sensitivity, detection accuracy, and application versatility, paving the way for advanced developments in biosensing technology with far-reaching implications for chemical and biomedical research.

Surface electric field enhanced biosensor based on symmetrical U-tapered HCF structure for gastric carcinoma biomarker trace detection

In this article, a novel U-tapered hollow-core fiber (HCF) surface plasmon resonance (SPR) biosensor coated with PtS2 for early-stage gastric carcinoma (GC) diagnosis was demonstrated. The article proposed the first investigation to detect Interleukin-10 (IL10) and Interleukin-1β (IL1β) which were associated with the risk of developing gastric carcinoma, using optical fiber SPR technology. Herein, the sensitivity of sensor was effectively improved through a combination of tapered and U-shaped structures. Additionally, to further enhance the detection capability, two-dimensional material PtS2 was utilized to increase the surface electric field intensity of the sensor. Simultaneously, optimization of structural parameters such as taper ratio, bending diameters, and Au film thickness was conducted. Ultimately, the designed sensor achieved a remarkable sensitivity of 13210 nm/RIU within the refractive index (RI) range of 1.33–1.37. The sensor demonstrated exceptional performance, achieving sensitivities of 3.64 nm/(ng/ml) and 7.46 nm/(ng/ml) for the detection of IL10 and IL1β biomarkers, respectively, along with limit of detection (LOD) of 2.74 pg/ml and 1.33 pg/ml, and successfully detecting the presence of these biomarkers in the serum of gastric cancer patients. Overall, the proposed sensor exhibits significant potential in early gastric cancer detection and advances the application of optical fiber SPR sensors in trace biodetection.

Citrate polymer optical fiber for measuring refractive index based on LSPR sensor

Fiber optic localized surface plasmon resonance (LSPR) sensors have become an effective tool in refractive index (RI) detection for biomedical applications because of their high sensitivity. However, using conventional optical fiber has caused limitations in implanting the sensor in the body. This research presents the design and construction of a new type of polymer-based LSPR sensors to address this issue. Also, finite element method (FEM) is used to design the sensor and test it theoretically. The proposed polymer optical fiber (POF) based on citrate is biocompatible, flexible, and degradable, with a rate of 22% and 27 over 12 days. The step RI structure utilizes two polymers for light transmission: poly (octamethylene maleate citrate) (POMC) as the core and poly (octamethylene citrate) (POC) as the cladding. The POF core and cladding diameters and lengths are 700 µm, 1400 µm, and 7 cm, respectively. The coupling efficiency of light to the POF was enhanced using a microsphere fiber optic tip. The obtained results show that the light coupling efficiency increased to 77.8%. Plasma surface treatment was used to immobilize gold nanoparticles (AuNPs) on the tip of the POF, as a LSPR-POF sensor. Adsorption kinetics was measured based on the pseudo-first-order model to determine the efficiency of immobilizing AuNPs, in which the adsorption rate constant (k) was obtained be 8.6 × 10–3 min−1. The RI sensitivity of the sensor in the range from 1.3332 to 1.3604 RIU was obtained as 7778%/RIU, and the sensitivity was enhanced ~ 5 times to the previous RI POF sensors. These results are in good agreement with theory and computer simulation. It promises a highly sensitive and label-free detection biosensor for point-of-care applications such as neurosciences.

Highly sensitive near-field leakage-enhanced optical fiber SPR sensor based on gold nanoarrays modulation

A novel near-field leakage-enhanced optical fiber surface plasmon resonance (NLF-SPR) sensor based on the synergistic sensitization of cuboid gold nanoarrays and WSe2 film is proposed for the first time to our knowledge. The sensor is composed of a side-polished multimode fiber, a continuous gold film, a continuous tungsten selenide (WSe2) film, and well-arranged cuboid gold nanoarrays. The sensor leverages the high carrier mobility characteristic of the WSe2 film, the near-field leakage enhancement arising from the nanoarrays structure, and the localized electric field enhancement property introduced by nanotips to enhance the refractive index sensitivity. In order to optimize the spectral characteristic, the modulation of electric field distribution and spectral characteristic by the structural parameters of gold nanoarrays is investigated through three-dimensional (3D) finite element simulation. Results show that in the refractive index range of 1.3332–1.3432 refractive index unit (RIU), the average sensitivity of the NLF-SPR sensor can reach up to 10108 nm/RIU, and the highest sensitivity can reach up to 14692.46 nm/RIU. The average sensitivity and the highest sensitivity are 1.87 times and 2.56 times higher, respectively, than those of the side-polished fiber SPR sensor with a monolayer gold film. Furthermore, the experimental results demonstrate that the near-field leakage enhancement introduced by gold nanoarrays improves the performance of the fiber SPR sensor, resulting in a 49.3 % increment in sensitivity. The experimental results are in agreement with the trend of the simulation results. Even better performance improvements have been achieved compared to existing methods and a more flexible approach to performance tuning is provided. With the maturity and development of various nanoarray processing techniques such as focused ion beam, electron beam lithography, and nanoimprint lithography, the proposed NLF-SPR sensor has the potential to be fabricated on a large scale and is expected to be widely employed in biomedical, clinical applications, and other fields.

Optical fiber sensor based on magneto-optical surface plasmon resonance with ultra-high figure of merit

Compared to surface plasmon resonance (SPR), the sensors based on the magneto-optical SPR (MOSPR) technique have much higher figure-of-merit (FOM). However, there are no reports about applying MOSPR in the optical fiber structure now. In this work, a novel D-shaped optical fiber sensor based on the MOSPR technique is proposed. The D-shaped optical fiber is coated with a thin silver film and a magneto-optical (MO) material film of Cerium-doped Yttrium-Iron garnet (CeYIG). By applying a magnetic field on the sensing region, the magneto-optical Kerr effect (MOKE) of the CeYIG layer and the related MOSPR phenomenon could be excited when appropriate light is transmitted in the proposed optical fiber sensor. The influence of the structural parameters including the residual cladding thickness, silver and MO material film thicknesses are analyzed theoretically by the finite element method (FEM). With the optimal parameters, the sensor achieves the sensitivity of 5304 nm RIU−1. Since the peak width of MOSPR spectra is much narrower than that of the SPR spectra, the FOM of the sensor is largely enhanced to 3864 RIU−1 on average and 13260 RIU−1 in maximum, which surpasses the optical fiber SPR sensors vastly. The miniaturized and simple design of the D-shaped optical fiber MOSPR sensor, coupled with the ultra-high FOM, offers itself great potential in biochemical sensing applications.

Triple-Channel Optical Fiber Surface Plasmon Resonance Sensor for Simultaneous Detection of Relative Humidity, Magnetic Field, and Temperature

Triple-Channel Optical Fiber Surface Plasmon Resonance Sensor for Simultaneous Detection of Relative Humidity, Magnetic Field, and Temperature

Side-Opened Hollow Fiber-Based SPR Sensor for High Refractive Index Detection.

To facilitate the sensor fabrication and sensing operation in microstructured optical fiber-based surface plasmon resonance (SPR) sensors for high refractive index (RI) detection, we propose a special hollow fiber-based SPR sensor that comprises an opening on its body side and a thin gold layer coated on its outer surface. The analyte is able to flow into the hollow core through the side-opening to form new fiber core, with the Gaussian-like mode propagating in it. We investigate the sensing performance of the proposed sensor in a higher RI range of 1.48 to 1.54 at two feasible schemes: one is to only fill the fiber core with analyte (Scheme A), and the other is to directly immerse the sensor in the analyte (Scheme B). The results demonstrate that our sensor exhibits higher wavelength sensitivity at Scheme A with a maximum wavelength sensitivity of 12,320 nm/RIU, while a greater amplitude sensitivity was found at Scheme B with a maximum amplitude sensitivity of 1146 RIU-1. Our proposed sensor features the advantages of simple fabrication, flexible operation, easy analyte filling and replacing, enhanced real-time detection capabilities, high RI detection, and very high wavelength sensitivity and amplitude sensitivity, which makes it more competitive in SPR sensing applications.

Copper and Tungsten Disulfide Based Highly Sensitive Fiber Optic Surface Plasmon Resonance Sensor

ABSTRACT Fiber optic surface plasmon resonance (SPR) sensor based on copper and tungsten disulfide is presented experimentally. The method of wavelength interrogation is used to analyze the sensor. Outcomes of thicknesses of these materials on the sensitivity of the sensor have been shown in detail. The presence of tungsten disulfide layer of certain thickness in the copper-based sensor has been shown to improve the sensitivity. The SPR sensor with 40 nm thick copper-10 nm thick tungsten disulfide layers exhibits highest sensitivity.

S-shaped tellurite optical fiber surface plasmon resonance sensor for temperature and refractive index measurement

In this paper, an all-fiber S-shaped structure optical fiber surface plasmon resonance (SPR) sensor is proposed for temperature and refractive index measurement. The sensor is made of a single-mode tellurite optical fiber (TOF), and the middle part of the single-mode TOF is heated by a ceramic heating rod to form an S-shaped sensing region, and a 50 nm gold film is deposited in the S-shape sensing area to excite SPR. Based on the excellent properties of tellurite optical fiber, the prepared optical fiber sensor can be used for high sensitivity temperature and refractive index detection. The highest refractive index sensitivity is up to 1068.59 nm/RIU in the range of 1.333–1.380, and the temperature sensitivity is up to −0.713 nm/°C in the range of 30–150 °C. The proposed sensor is simple to fabricate, low-cost, and compact, and can be widely used in biochemical analysis, complex environmental temperature monitoring and other fields.

Corrosive Pseudomonas aeruginosa detection by measuring pyocyanin with a lab-on-fiber optical surface plasmon resonance biosensor in aquatic environments

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.

Temperature self-compensated fiber-optic Pb(II) sensor with improved selectivity by Resorcylaldehyde post-modified organic metal framework

Post-modification of metal-organic framework (MOF) materials is an effective means to enhance their efficient and selective adsorption for heavy metal ions. In this article, we presented a reflection-type optical fiber surface plasmon resonance (SPR) sensor based on dual core fiber (DCF) coated with UiO-66-RSA (UiO-66-NH2 post-modified with resorcinol aldehyde) film for the specific detection of Pb(II) in aqueous media. The composite material UiO-66-RSA exhibits stronger affinity and specificity for Pb(II) than UiO-66-NH2. The adsorption of Pb(II) can change the equivalent refractive index (RI) of UiO-66-RSA film, causing a regular shift in SPR spectra. Experiments have shown that the limit of detection (LOD) of the SPR Pb(II) sensor can reach 0.1 nM. Meanwhile, research has found that the SPR sensor is accompanied by temperature crosstalk of 0.356 nm/°C. Therefore, we constructed a Michelson temperature interferometer using polymer micro tips on the end face of the fiber core to achieve temperature compensation. Based on the above two sensing channels, dual parameter demodulation of Pb(II) concentration and temperature can be achieved with an error rate of less than 0.5 %. This article has potential research value in exploring the application of post modification techniques of MOF in fiber optic lead ion detection.

Reflective optical fiber SPR sensor with DNA modification for high-sensitive Hg2+ concentration measurement

A reflective optical fiber surface plasmon resonance (SPR) sensor was proposed to measure the concentration of mercury ions (Hg2+). The specific single-stranded DNA was modified on the optical fiber sensing surface coated with Au film by the combination of covalent bond and charge adsorption. The Hg2+ can mismatch with T-T (thymine-thymine) base pairs in single-stranded DNA to form T-Hg2+-T structure, which led to the change of refractive index in sensing area and the wavelength shift of SPR spectrum. The measurement results showed that when the concentration of Hg2+ increased from 0 μM to 13 μM, the resonance spectrum shifted by 14.26 nm. In the linear range between 1–8 μM, the measurement sensitivity of the sensor could reach 1.51 nm/μM. The limit of detection (LOD) was found to be 0.28 μM. Besides, the sensor showed good stability, selectivity and reusability.

High sensitive optical fiber SPR sensor for label-free detection of Staphylococcus aureus

Optical fiber bacterial sensors have attracted attention in many fields due to their unique advantages. However, it is still difficult to promote its practicality which is mainly subject to their low sensitivity, inferior stability, and reliability. This work reported here an optical fiber surface plasmon resonance (SPR) biosensor enhanced by gold nanoparticles (AuNPs)/Au film coupling for label-free detection the Staphylococcus aureus (S. aureus), while both the gold substrates were successfully biofunctionalized with goat anti-human immunoglobulin G (IgG) as the probe to capture and detect the bacteria. In the experiment, the refractive index（RI） sensitivity of the Multimode-Singlemode-Multimode optical fiber (MSMOF) coated with Au film was improved by 19 % after the AuNPs were homogeneously decorated on the Au film surface. To detect S. aureus by the sensor, the SPR wavelength variation in the transmission spectrum was recorded, and its limit of detection (LOD) was demonstrated experimentally to be about 50 CFU/mL and was obtained theoretically to be 1.18 CFU/mL during its concentration range of 50–108 CFU/mL. Also, it shows great linearity in the range of 102-108 CFU/mL and the sensor exhibits excellent specificity and stability. This kind of SPR-enhanced optical fiber biosensor is fully promising for its applications in biomedicine, food safety, pharmaceuticals, etc.

Optical fiber surface plasmon resonance sensor using electroless-plated gold film for thrombin detection.

This paper describes the simple and label-free detection of thrombin using optical fiber surface plasmon resonance (SPR) sensors based on gold films prepared by the cost-effective method of electroless plating. The plating conditions for simultaneously obtaining gold film on cylindrical core and end surfaces of anoptical fiber suitable for measurement were optimized. The fabricated sensor exhibited a linear refractive index sensitivity of 2150 nm/RIU and 7.136 (a.u.)/RIU in the refractive index of 1.3329-1.3605 interrogated by resonance wavelength and amplitude methods respectively and a single wavelength monitoring method was proposed to investigate the sensing performance of this sensor. Polyadenine diblock and thiolated thrombin aptamers were immobilized on gold nanoparticles and gold films respectively to implement asandwich optical fiber assay for thrombin. The developed optical fiber SPR sensors were successfully used in the determination of thrombin down to 0.56 nM over a wide range from 2 to 100 nM and showed good selectivity for thrombin, which indicated their potential clinical applications for biomedical samples.

MMF-SMF-MMF optic surface plasmon resonance sensor based on hexagonal plate-like [formula omitted] structure

The manuscript introduces a fiber-optic MSM SPR sensor employing a hexagonal plate-like structure of Co(OH)2/TiO2/Au for surface plasmon resonance (SPR) sensing. This article aims to improve it through optimization of material composition and structure. The MSM structure SPR sensors were fabricated on the surface of single-mode fiber optic using chemical precipitation and physical vapor deposition, where Co(OH)2 and TiO2 served as sensitive materials. The experimental results demonstrate that the proposed sensor exhibited significantly higher sensitivity and broader application potential than the gold film control group and the gold film/TiO2 control group. Specifically, the gold film control group had a sensitivity of 1778.44 nm/RIU, while the sensitivity of the TiO2/Au control group was 2230.9 nm/RIU. In contrast, the Co(OH)2/TiO2/Au structure SPR sensor had a sensitivity of 3106.5 nm/RIU, which is far superior to the two control groups. Moreover, the results of repeated measurements indicated that the resonant wavelength error was only within 2 nm. These findings suggest that the Co(OH)2/TiO2/Au structure SPR sensor has promising stability and repeatability, making it suitable for applications in various fields, including chemical sensing and biological sensing.

Silver-coated hollow fiber surface plasmon resonance sensor for glucose detection with enhanced limit of detection.

A fiber-optic surface plasmon resonance (SPR) biosensor based on a silver-coated hollow fiber (HF) structure for glucose detection is presented. The sensor surface was immobilized with 4-mercaptophenylboronic acid (PMBA) acting as a glucose recognition monolayer. Then, gold nanoparticles (AuNPs) modified with 2-aminoethanethiol (2-AET) and PMBA were introduced onto the sensor surface after glucose was captured to enhance the wavelength shift of the SPR phenomenon excited by the light transmitted in the wall of the HF sensor. Instead of the conventional one-step sensitization pretreatment commonly used in the deposition process of silver films for fiber-optic SPR sensors, a sensitization-activation two-step activation method was adopted in the fabrication of the proposed sensor. Experiments for glucose detection were performed on the fabricated sensors in the concentration range of 1 nM-1 mM. Results showed that the sensor fabricated by the two-step activation method has a much larger shift of resonance wavelength than the sensor fabricated using the one-step sensitization method. The resonance wavelength shift was found to be linear to the logarithm of the concentration in the range of 1 nM-1 mM. The sensor achieved a limit of detection (LOD) of as low as 1 nM, which is at least an order of magnitude lower than that of other fiber-optic sensors for glucose detection reported previously. The presented HF glucose sensor has the potential for biosensing applications and provides a large reference value in the study of optical fiber SPR sensors for biosensing.