Home Physical Sciences High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure
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High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure

  • Pengxiang Chang , Yirui Zhang , Ailing Zhang ORCID logo EMAIL logo , Zhen Li , Zhiyang Wang and Yanmei Shi
Published/Copyright: December 1, 2025
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Nanophotonics
From the journal Nanophotonics Volume 14 Issue 27

Abstract

Combining the advantages of polydopamine (PDA), gold nanoparticles (AuNPs), and U-shaped optical fibers, a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber surface plasmon resonance (SPR) biosensor was proposed and used for the detection of rabbit IgG. The U-shaped structure significantly enhances the penetration depth of the evanescent field. The PDA/AuNPs/PDA sandwich structure boosts coupling efficiency of SPR and LSPR, increases the specific surface area of the sensor, and improves surface activity. The experimental results show that the refractive index (RI) sensitivity of the sensor is 6,206.32 nm/RIU in the RI range of 1.3353–1.3595, which is 1.63 times higher than the raw U-shaped sensor. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and a limit of detection (LOD) of 0.131 ng/mL, which is one order of magnitude lower. The outstanding performance of the proposed biosensor offers a new solution for the detection of low-concentration biological solutions, and it has great potential applications in the field of medical diagnosis.

Keywords: surface plasmon resonance; U-shaped; gold nanoparticles; biosensor; rabbit IgG; polydopamine

1 Introduction

Rapid and accurate detection of biomarkers is crucial for modern medical diagnostics, especially for early disease detection and personalized healthcare. Biosensors, which convert biological interactions into measurable signal, have become indispensable tools in the clinical and research fields due to their specificity, portability and real-time monitoring capabilities [1]. Among the traditional methods for biomolecular detection, electrochemical technique [2] is prone to passivation. Secondly, enzyme-linked immunosorbent assay (ELISA) [3] requires multiple incubation and washing steps, which are time-consuming. In contrast, label-free biosensors (such as surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR)) utilize the specific binding of antibodies to antigens to detect antigen molecules. This process is simple, controllable, and has high detection capabilities. Although SPR sensors have the above advantages, the LOD of sensor performance and detectable target types still needs to be improved.

The current methods for improving SPR sensor performance mainly include structural sensitization and material sensitization (coupling effects, surface activation and so on). The geometry of the optic fiber plays a key role to improve the sensor performance. Compared to conventional sensor configuration, the U-shaped structure significantly enhances the evanescent field intensity of the sensor surface [4]. Zhou and Yan (2022) developed MXene-based D-shaped SPR sensor, achieving refractive index (RI) sensitivity of 3,143 nm/RIU [5]. Although the D-shaped structure can improve the sensitivity of the sensor, its grinding process is uncontrollable and difficult to manufacture. Subsequently, Wei et al. introduced the S-taper structure into single-mode fiber, which increased the sensitivity to 3,244.62 nm/RIU [6]. However, this precision-dependent tapering technique has limitations in high-precision RI detection, and the sensor is difficult to manufacture. In contrast, Wang et al. introduced a U-shaped structure, which increased sensitivity to 3,808.74 nm/RIU [7]. Compared with the other two sensors, it is easy to manufacture and can achieve high-precision detection. Furthermore, it can be designed as a plug-and-play. However, while the U-shaped structure can significantly improve RI sensitivity of the sensor, the ability of this type of sensor to detect biomolecules is still limited by improvements in the functionalized membrane layer.

Recent advances in nanomaterial development have pioneered novel approaches for functionalized film modification in SPR sensors. LSPR generated by metallic nanoparticles has been widely used to enhance electric field confinement and improve RI sensitivity of optical fiber biosensor [8]. The coupling between SPR and LSPR can significantly enhance sensor performance [9]. For example, Wang et al. (2018) demonstrated a hybrid SPR/LSPR biosensor with AuNps, which significant increase RI sensitivity compared to normal SPR sensor [10]. Similarly, Ding et al. reported a novel sensitive SPR cortisol aptamer sensor based on the coupling effect of AuNPs and Au thin films, which showed a 40 % increase in sensitivity over the sensor without AuNPs modification [11]. From the above literature review, it can be seen that nanomaterial can significantly improve the physical properties of sensors, but they cannot enhance the surface activity of sensors. Therefore, it is necessary to introduce a type of biomaterial to enhance the surface activity of sensors.

To address these challenges, polydopamine (PDA) was applied to optic fiber SPR sensors. PDA self-polymerize into a functional film on sensor surfaces with abundant active sites [12], [13]. This film can immobilize AuNPs and adsorbing biomolecules, thereby enhance sensor RI sensitivity and surface reactivity [14]. Recent studies by Gao et al. have highlighted the dual role of PDA in improving sensor stability and acting as a substrate for antibody immobilization [15]. Cao et al. found that SPR sensors modified with PDA nanospheres achieved RI sensitivity of 2,427 nm/RIU, which is 55.7 % higher than raw sensor. When the sensor was used to detect C-reactive protein, a limit of detection (LOD) reached 0.22 μg/mL [16]. Zhang et al. (2025) developed an SPR sensor modified with Fe3O4@Au@PDA, which had an LOD of 0.61 ng/mL when detecting tebuconazole [17].

We proposed a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber SPR biosensor. Compared with the raw sensor, the developed SPR biosensor exhibits higher sensitivity and low LOD. In addition, the PDA/AuNPs/PDA modified biosensor was used for the specific detection of rabbit IgG concentration. The evaluation and comparison of the fabricated biosensor with other reported SPR biosensors revealed the promising potential of our developed optical fiber SPR biosensor for the medical diagnosis.

2 Materials and methods

2.1 Materials

MMF (core/cladding layer diameter of 62.5/125 µm, purchased from Changfei Optical Fiber Company), AuNPs dispersion (particle size of 10 nm, concentration of 10 mg/mL), purchased from DEK Daojin, dopamine hydrochloride (DA, 98 %), bovine serum albumin (BSA) dry powder, rabbit IgG solution, goat anti-rabbit IgG protein solution, human IgG solution, phosphate buffer solution (PBS, 10 Mm), 10 mM Tris buffer (pH 8.9), which were purchased from Aladdin Co. 8.9.

2.2 Experimental methods

The optical fiber SPR biosensor is shown in Figure 1 The system consists of four components, a broadband light source (model HL2000, ocean optics, spectral range 200 nm–1,200 nm), an optic fiber SPR biosensor, a visible light spectrometer (model HR 4000, ocean optics, detection range 296 nm–1,080 nm with a resolution 0.02 nm) and a computer for signal demodulation, display and storage. Light from the broadband light source passes through the fiber SPR biosensor, exciting the SPR phenomenon and causing attenuation of the light signal at specific wavelengths. The attenuated light signal is detected by spectrometer and the SPR resonance wavelength is extracted from the minimum value of the normalized transmission spectrum using the centroid method.

Figure 1: Experimental setup for optical fiber SPR biosensor: (a) Schematic diagram of U-shaped SPR sensor. (b) Physical diagram of U-shaped sensor with a bending diameter of 2 mm.
Figure 1:

Experimental setup for optical fiber SPR biosensor: (a) Schematic diagram of U-shaped SPR sensor. (b) Physical diagram of U-shaped sensor with a bending diameter of 2 mm.

2.3 Preparation of optical fiber SPR sensor

The schematic diagram of preparation is shown in Figure 6 First, the coating layer of the MMF is removed to expose the cladding layer (as shown in Figure 2(a)). The exposed cladding layer is heated with hydrogen-oxygen flame to bend into a U-shaped structure with a diameter of 2 mm (as shown in Figure 1(b) and Figure 2(b)). The sensing area was coated with Au film by magnetron sputtering system. The thickness of Au film was 50 nm. (as shown in Figure 2(c)). To avoid the influence of impurities on the biological experiments, all instruments used in the experiments were thoroughly cleaned in an ultrasonic cleaner.

Figure 2: Schematic representation of the surface functionalization of the biosensor based on U-shape PDA/AuNPs/PDA structure: (a) MMF optical fiber after the removal of the coating layer. (b) The MMF is bent into a U-shape by heating it with a hydrogen-oxygen flame. (c) Sensor coated with an Au film. (d) Sensor modified with PDA. (e) Sensor modified with AuNPs. (f) Sensor modified with PDA. (g) Sensor coated with goat anti-rabbit IgG. (h) Blocking of the residual active sites on the SPR biosensor with BSA. (l) Fabrication of the biosensor for the specific detection of rabbit IgG.
Figure 2:

Schematic representation of the surface functionalization of the biosensor based on U-shape PDA/AuNPs/PDA structure: (a) MMF optical fiber after the removal of the coating layer. (b) The MMF is bent into a U-shape by heating it with a hydrogen-oxygen flame. (c) Sensor coated with an Au film. (d) Sensor modified with PDA. (e) Sensor modified with AuNPs. (f) Sensor modified with PDA. (g) Sensor coated with goat anti-rabbit IgG. (h) Blocking of the residual active sites on the SPR biosensor with BSA. (l) Fabrication of the biosensor for the specific detection of rabbit IgG.

To further modify AuNPs onto the sensor, the raw SPR sensor was first immersed in the PDA solution and placed in an incubator oscillating at 120 rpm. After 20 min of oscillation, the sensor was rinsed with deionized water and followed by air-drying to facilitate PDA on the sensor surface (as shown in Figure 2(d)). After that, the sensor was immersed in the AuNPs dispersion solution for 1 h and rinsed with deionized water (as shown in Figure 2(e)). Figure 3 is the scanning electron microscope image of the manufactured sensor. As can be seen from the figure, AuNPs are uniformly deposited on the sensor surface, with a particle size of approximately 10 nm. Figure 4 shows the energy dispersive X-ray spectrum of the sensor surface. The elements C and N were detected, indicating that PDA is fixed to the fiber surface.

Figure 3: The scanning electron microscope image of the fabricated sensor.
Figure 3:

The scanning electron microscope image of the fabricated sensor.

Figure 4: The energy dispersive X-ray spectrum (EDX) of the sensor surface.
Figure 4:

The energy dispersive X-ray spectrum (EDX) of the sensor surface.

The next step is fixing goat anti-rabbit IgG on the sensor surface. The sensor head was firstly coated by PDA film (as shown in Figure 2(f)) and then was immersed into goat anti-rabbit IgG solution (100 μg/mL of PBS buffer). After refrigeration at 4 °C for 24 h (as shown in Figure 2(g)), the sensor head was immersed in BSA solution (10 mg/mL) for 1 h to block remaining active sites on the sensor surface (as shown in Figure 2(h)). Finally, the sensor was immersed in different concentrations of rabbit IgG dilutions (diluted with PBS buffer) for 10 min at 37 °C (as shown in Figure 2(l)) to monitor the drift of the sensor resonance wavelength.

3 Results and discussion

3.1 Measurement of RI sensitivity

In order to evaluate the performance of U-shaped sensor different RI value glycerol solutions (RI solutions of 1.3353, 1.3393, 1.3447, 1.3496, 1.3542, and 1.3595) were carried out at room temperature. The transmission spectra of the raw U-shaped sensor and the U-shaped sensor modified with PDA/AuNPs are shown in Figure 5(a) and (b). An increase in the refractive index leads to the phase-matching condition for the proposed multi-layer structure being satisfied at a longer wavelength. Figure 5(c) is the resonance wavelength versus RI for both types of sensors, the RI sensitivity of the sensor increased from 3,793.99 nm/RIU to 6,206.32 nm/RIU, which is 1.63 times higher than RI sensitivity of the raw U-shaped sensor. This sensitivity enhancement is caused by the enhanced electric field surrounding the sensor, which results from the coupling of SPR/LSPR and the high RI of PDA.

Figure 5: Performance characterization of the U-shaped SPR sensors: (a) Resonance spectra of U-shaped SPR sensor in different RI analytes, (b) Resonance spectra of U-shaped SPR sensor modified with AuNPs and PDA in different RI analytes, and (c) the resonance wavelength versus RI for both types of sensors.
Figure 5:

Performance characterization of the U-shaped SPR sensors: (a) Resonance spectra of U-shaped SPR sensor in different RI analytes, (b) Resonance spectra of U-shaped SPR sensor modified with AuNPs and PDA in different RI analytes, and (c) the resonance wavelength versus RI for both types of sensors.

The sensitivity enhancement by the PDA/AuNPs structure was also verified via simulations. The simulation structures without PDA/AuNPs and with PDA/AuNPs are schematically illustrated in Figure 6. The simulation results are shown in Figure 7. The results indicate that the RI sensitivity of the fiber optic SPR sensor with PDA/AuNPs is 2.43 times higher than that of the sensor without PDA/AuNPs. The results confirm that the sensitivity enhancement is caused by the enhanced electric field around the sensor, caused by the coupling of SPR/LSPR and the high RI of PDA.

Figure 6: Schematic diagram of the sensor simulation structure: (a) Structural diagram of Au film-modified fiber SPR sensor, from outer to inner layers: 3.125 µm coreless optical fiber, 50 nm Au film and analyte. (b) Structural diagram of Au/PDA/AuNPs modified fiber SPR sensor, from outer to inner layers: 3.125 µm coreless optical fiber, 50 nm Au film, 20 nm PDA, AuNPs with a diameter of 20 nm and analyte.
Figure 6:

Schematic diagram of the sensor simulation structure: (a) Structural diagram of Au film-modified fiber SPR sensor, from outer to inner layers: 3.125 µm coreless optical fiber, 50 nm Au film and analyte. (b) Structural diagram of Au/PDA/AuNPs modified fiber SPR sensor, from outer to inner layers: 3.125 µm coreless optical fiber, 50 nm Au film, 20 nm PDA, AuNPs with a diameter of 20 nm and analyte.

Figure 7: The resonance wavelength versus RI for both types of sensors.
Figure 7:

The resonance wavelength versus RI for both types of sensors.

3.2 Application for rabbit IgG specificity detection

To evaluate the biosensitivity of the sensor, different concentrations of rabbit IgG solutions (0.02, 0.04, 0.06, 0.08, 1.00, 10.00 μg/mL) were injected into the reaction tube and the resonance wavelength was recorded in real time by a computer. When detecting for specific IgG concentration, the biosensor was rinsed three times with NaOH solution (10 mM) to wash away the antigen-antibody specific binding. As shown in Figure 8(a), the resonance wavelength of the sensor not only varied with the increase of rabbit IgG concentration, but also showed a gradual saturation response over time. This indicates that specific binding between rabbit IgG and goat anti-rabbit IgG is occurring and the immune response is gradually completed. The relationship between the concentration of rabbit IgG and the shift of the SPR curve is shown in Figure 8(b). The red line indicates the linear fit between the SPR curve and the rabbit IgG concentration (0.02–0.10 μg/mL). Within this linear fit range, the biosensor achieved a bio sensitivity of 0.153 nm/(ng/mL) for rabbit IgG with a fit coefficient of 0.998. The LOD was also used to evaluate the performance of the biosensor, which was defined as

(1) L O D = λ S S b i o

where λ S represents the resolution of the spectrometer. The LOD of the biosensor was calculated as 0.131 ng/mL.

Figure 8: Detection performance for rabbit IgG using a U-shaped biosensor with a PDA/AuNPs/PDA sandwich structure: (a) SPR curves with time at different concentrations of rabbit IgG, (b) linear fit between rabbit IgG concentration and sensor resonance wavelength.
Figure 8:

Detection performance for rabbit IgG using a U-shaped biosensor with a PDA/AuNPs/PDA sandwich structure: (a) SPR curves with time at different concentrations of rabbit IgG, (b) linear fit between rabbit IgG concentration and sensor resonance wavelength.

3.3 Specificity and repeatability studies

To assess the specificity of the PDA/AuNPs/PDA modified optic fiber SPR biosensor, BSA, human IgG and rabbit IgG solutions were used to evaluate the binding efficiency. Goat anti-rabbit IgG was used as a stationary antibody and protein solutions were introduced sequentially at a concentration of 100 μg/mL as a comparison experiment. Figure 9 illustrates that the resonance wavelength remained essentially unchanged when the interfering BSA and human IgG were detected. However, the wavelength shift corresponding to rabbit IgG was much higher than the other two, indicating that the sensor fulfils the purpose of specific detection. The excellent specificity of the biosensor based on PDA/AuNPs/PDA modification was demonstrated.

Figure 9: Resonance wavelength shifted IgG of human IgG, BSA and rabbit.
Figure 9:

Resonance wavelength shifted IgG of human IgG, BSA and rabbit.

The reusability of the sensor for 20 ng/ml rabbit IgG solution is shown in Figure 10 with NaOH solution cleaning between each measurement. It shows good repeatability. After 10 times NaOH solution cleaning, the Au film was observed to detach, which prevented further replication of the experiment. Reproducible detection may be in the future by improving the immobilization process of the sensor and the Au film.

Figure 10: The repetitive performance experiments of the sensor.
Figure 10:

The repetitive performance experiments of the sensor.

3.4 Performance comparison of biosensors

The comparison between the proposed sensor and reported sensors in terms of biosensitivity and LOD is shown in Table 1. The biosensitivity of the proposed U-shaped biosensor is two orders of magnitude higher and the LOD is one order of magnitude lower than that of the biosensors in Table 1. This significant enhancement stems from the synergistic contributions of the U-shaped optical fiber architecture and the PDA/AuNPs/PDA sandwich structure. The U-shaped structure physically increases the penetration depth of the evanescent field. And the PDA/AuNPs/PDA sandwich structure not only improves the coupling efficiency between SPR and LSPR, also enhances surface reactivity through enlarging the functional surface area by PDA. In conclusion, the multilayered architecture on U-shaped MMF significantly enhances the RI sensitivity and biomolecular immobilization efficiency, which leads to an improved bio-sensitivity and a lower LOD for the proposed biosensor.

Table 1:

Comparison of biosensor performance of different methods.

Methods used Analyte Structure Material Bio-sensitivity nm/(ng/mL) LOD ng/mL Ref.
LSPR Rabbit IgG SPR sensor AuNR@SiO2 N.A. 12 [18]
Goat-anti-human IgG D-shaped PCF AuNPs N.A. 600 [19]
SPR Human IgG SPR sensor Biotin-streptavidin sandwich integrated PDA-ZnO@Au N.A. 37.5 [20]
Human IgG S-shaped SPR sensor Au/TiO2 0.006025 1.66 [21]
Human IgG U-shaped MMF MoS2/Au film/PDA 0.001014 19.7 [22]
Rabbit IgG POF PNs 0.0014 15 [1]
Goat-anti-rabbit IgG POF PDA-MoSe2@AuNPs-PDA 0.00037 54 [23]
Human IgG MSM Ti3C2TxMXene/AuNPs/Au 0.0017 170 [24]
Human IgG POF Ag@Au/GO 0.00053 37 [25]
Rabbit IgG U-shaped MMF PDA/AuNPs/PDA 0.153 0.131 This work

4 Conclusions

A highly sensitive U-shaped SPR biosensor is demonstrated in this paper, which utilizes the synergistic enhancement of the U-shaped optical fiber architecture and the PDA/AuNPs/PDA sandwich structure. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and LOD of 0.131 ng/mL, which is one order of magnitude lower. The significantly improved performance of the proposed biosensor enables potential applications in medical diagnosis.

Corresponding author: Ailing Zhang, Tianjin Key Laboratory of Thin Film Electronics and Communication Devices, Engineering Research Center of Optoelectronic Devices and Communication Technology, Ministry of Education, College of Integrated Circuit Science and Engineering, Tianjin University of Technology, Tianjin 300384, China, E-mail:

Funding source: Tianjin Natural Science Foundation

Award Identifier / Grant number: No. 20JCZDJC00500

Acknowledgements

The authors would like to express their sincere gratitude to Dr. Zhang for the invaluable guidance, mentorship, and encouragement throughout the completion of this research paper.

  1. Research funding: This work was supported by Tianjin Natural Science Foundation under grant No. 20JCZDJC00500.

  2. Author contributions: PC: resources, data management, conceptualization, formal analysis, writing review and editing. YZ: writing review and editing, writing the first draft, methodology, research, drawing. AZ: writing review and editing, instruction, formal analysis, data management. YS: mentoring. ZW: visualization. ZL: conceptualization. All authors have accepted responsibility for the entire content of this manuscript and consented to its submission to the journal, reviewed all the results and approved the final version of the manuscript.

  3. Conflict of interest: Authors state no conflicts of interest.

  4. Data availability: The data that support the findings of this study are available within the article.

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Received: 2025-08-02
Accepted: 2025-11-17
Published Online: 2025-12-01

© 2025 the author(s), published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution 4.0 International License.

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  25. Metastructure-enabled scalable multiple mode-order converters: conceptual design and demonstration in direct-access add/drop multiplexing systems
  26. High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure
  27. Deep-learning-based polarization-dependent switching metasurface in dual-band for optical communication
  28. A nonlocal metasurface for optical edge detection in the far-field
  29. Coexistence of weak and strong coupling in a photonic molecule through dissipative coupling to a quantum dot
  30. Mitigate the variation of energy band gap with electric field induced by quantum confinement Stark effect via a gradient quantum system for frequency-stable laser diodes
  31. Orthogonal canalized polaritons via coupling graphene plasmon and phonon polaritons of hBN metasurface
  32. Dual-polarization electromagnetic window simultaneously with extreme in-band angle-stability and out-of-band RCS reduction empowered by flip-coding metasurface
  33. Record-level, exceptionally broadband borophene-based absorber with near-perfect absorption: design and comparison with a graphene-based counterpart
  34. Generalized non-Hermitian Hamiltonian for guided resonances in photonic crystal slabs
  35. A 10× continuously zoomable metalens system with super-wide field of view and near-diffraction–limited resolution
  36. Continuously tunable broadband adiabatic coupler for programmable photonic processors
  37. Diffraction order-engineered polarization-dependent silicon nano-antennas metagrating for compact subtissue Mueller microscopy
  38. Lithography-free subwavelength metacoatings for high thermal radiation background camouflage empowered by deep neural network
  39. Multicolor nanoring arrays with uniform and decoupled scattering for augmented reality displays
  40. Permittivity-asymmetric qBIC metasurfaces for refractive index sensing
  41. Theory of dynamical superradiance in organic materials
  42. Second-harmonic generation in NbOI2-integrated silicon nitride microdisk resonators
  43. A comprehensive study of plasmonic mode hybridization in gold nanoparticle-over-mirror (NPoM) arrays
  44. Foundry-enabled wafer-scale characterization and modeling of silicon photonic DWDM links
  45. Rough Fabry–Perot cavity: a vastly multi-scale numerical problem
  46. Classification of quantum-spin-hall topological phase in 2D photonic continuous media using electromagnetic parameters
  47. Light-guided spectral sculpting in chiral azobenzene-doped cholesteric liquid crystals for reconfigurable narrowband unpolarized light sources
  48. Modelling Purcell enhancement of metasurfaces supporting quasi-bound states in the continuum
  49. Ultranarrow polaritonic cavities formed by one-dimensional junctions of two-dimensional in-plane heterostructures
  50. Bridging the scalability gap in van der Waals light guiding with high refractive index MoTe2
  51. Ultrafast optical modulation of vibrational strong coupling in ReCl(CO)3(2,2-bipyridine)
  52. Chirality-driven all-optical image differentiation
  53. Wafer-scale CMOS foundry silicon-on-insulator devices for integrated temporal pulse compression
  54. Monolithic temperature-insensitive high-Q Ta2O5 microdisk resonator
  55. Nanogap-enhanced terahertz suppression of superconductivity
  56. Large-gap cascaded Moiré metasurfaces enabling switchable bright-field and phase-contrast imaging compatible with coherent and incoherent light
  57. Synergistic enhancement of magneto-optical response in cobalt-based metasurfaces via plasmonic, lattice, and cavity modes
  58. Scalable unitary computing using time-parallelized photonic lattices
  59. Diffusion model-based inverse design of photonic crystals for customized refraction
  60. Wafer-scale integration of photonic integrated circuits and atomic vapor cells
  61. Optical see-through augmented reality via inverse-designed waveguide couplers
  62. One-dimensional dielectric grating structure for plasmonic coupling and routing
  63. MCP-enabled LLM for meta-optics inverse design: leveraging differentiable solver without LLM expertise
  64. Broadband variable beamsplitter made of a subwavelength-thick metamaterial
  65. Scaling-dependent tunability of spin-driven photocurrents in magnetic metamaterials
  66. AI-based analysis algorithm incorporating nanoscale structural variations and measurement-angle misalignment in spectroscopic ellipsometry
https://doi.org/10.1515/nanoph-2025-0367
Keywords for this article
surface plasmon resonance; U-shaped; gold nanoparticles; biosensor; rabbit IgG; polydopamine
Creative Commons
BY 4.0

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  2. Reviews
  3. Light-driven micro/nanobots
  4. Tunable BIC metamaterials with Dirac semimetals
  5. Large-scale silicon photonics switches for AI/ML interconnections based on a 300-mm CMOS pilot line
  6. Perspective
  7. Density-functional tight binding meets Maxwell: unraveling the mysteries of (strong) light–matter coupling efficiently
  8. Letters
  9. Broadband on-chip spectral sensing via directly integrated narrowband plasmonic filters for computational multispectral imaging
  10. Sub-100 nm manipulation of blue light over a large field of view using Si nanolens array
  11. Tunable bound states in the continuum through hybridization of 1D and 2D metasurfaces
  12. Integrated array of coupled exciton–polariton condensates
  13. Disentangling the absorption lineshape of methylene blue for nanocavity strong coupling
  14. Research Articles
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  16. Inverse-designed gyrotropic scatterers for non-reciprocal analog computing
  17. Highly sensitive broadband photodetector based on PtSe2 photothermal effect and fiber harmonic Vernier effect
  18. Online training and pruning of multi-wavelength photonic neural networks
  19. Robust transport of high-speed data in a topological valley Hall insulator
  20. Engineering super- and sub-radiant hybrid plasmons in a tunable graphene frame-heptamer metasurface
  21. Near-unity fueling light into a single plasmonic nanocavity
  22. Polarization-dependent gain characterization in x-cut LNOI erbium-doped waveguide amplifiers
  23. Intramodal stimulated Brillouin scattering in suspended AlN waveguides
  24. Single-shot Stokes polarimetry of plasmon-coupled single-molecule fluorescence
  25. Metastructure-enabled scalable multiple mode-order converters: conceptual design and demonstration in direct-access add/drop multiplexing systems
  26. High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure
  27. Deep-learning-based polarization-dependent switching metasurface in dual-band for optical communication
  28. A nonlocal metasurface for optical edge detection in the far-field
  29. Coexistence of weak and strong coupling in a photonic molecule through dissipative coupling to a quantum dot
  30. Mitigate the variation of energy band gap with electric field induced by quantum confinement Stark effect via a gradient quantum system for frequency-stable laser diodes
  31. Orthogonal canalized polaritons via coupling graphene plasmon and phonon polaritons of hBN metasurface
  32. Dual-polarization electromagnetic window simultaneously with extreme in-band angle-stability and out-of-band RCS reduction empowered by flip-coding metasurface
  33. Record-level, exceptionally broadband borophene-based absorber with near-perfect absorption: design and comparison with a graphene-based counterpart
  34. Generalized non-Hermitian Hamiltonian for guided resonances in photonic crystal slabs
  35. A 10× continuously zoomable metalens system with super-wide field of view and near-diffraction–limited resolution
  36. Continuously tunable broadband adiabatic coupler for programmable photonic processors
  37. Diffraction order-engineered polarization-dependent silicon nano-antennas metagrating for compact subtissue Mueller microscopy
  38. Lithography-free subwavelength metacoatings for high thermal radiation background camouflage empowered by deep neural network
  39. Multicolor nanoring arrays with uniform and decoupled scattering for augmented reality displays
  40. Permittivity-asymmetric qBIC metasurfaces for refractive index sensing
  41. Theory of dynamical superradiance in organic materials
  42. Second-harmonic generation in NbOI2-integrated silicon nitride microdisk resonators
  43. A comprehensive study of plasmonic mode hybridization in gold nanoparticle-over-mirror (NPoM) arrays
  44. Foundry-enabled wafer-scale characterization and modeling of silicon photonic DWDM links
  45. Rough Fabry–Perot cavity: a vastly multi-scale numerical problem
  46. Classification of quantum-spin-hall topological phase in 2D photonic continuous media using electromagnetic parameters
  47. Light-guided spectral sculpting in chiral azobenzene-doped cholesteric liquid crystals for reconfigurable narrowband unpolarized light sources
  48. Modelling Purcell enhancement of metasurfaces supporting quasi-bound states in the continuum
  49. Ultranarrow polaritonic cavities formed by one-dimensional junctions of two-dimensional in-plane heterostructures
  50. Bridging the scalability gap in van der Waals light guiding with high refractive index MoTe2
  51. Ultrafast optical modulation of vibrational strong coupling in ReCl(CO)3(2,2-bipyridine)
  52. Chirality-driven all-optical image differentiation
  53. Wafer-scale CMOS foundry silicon-on-insulator devices for integrated temporal pulse compression
  54. Monolithic temperature-insensitive high-Q Ta2O5 microdisk resonator
  55. Nanogap-enhanced terahertz suppression of superconductivity
  56. Large-gap cascaded Moiré metasurfaces enabling switchable bright-field and phase-contrast imaging compatible with coherent and incoherent light
  57. Synergistic enhancement of magneto-optical response in cobalt-based metasurfaces via plasmonic, lattice, and cavity modes
  58. Scalable unitary computing using time-parallelized photonic lattices
  59. Diffusion model-based inverse design of photonic crystals for customized refraction
  60. Wafer-scale integration of photonic integrated circuits and atomic vapor cells
  61. Optical see-through augmented reality via inverse-designed waveguide couplers
  62. One-dimensional dielectric grating structure for plasmonic coupling and routing
  63. MCP-enabled LLM for meta-optics inverse design: leveraging differentiable solver without LLM expertise
  64. Broadband variable beamsplitter made of a subwavelength-thick metamaterial
  65. Scaling-dependent tunability of spin-driven photocurrents in magnetic metamaterials
  66. AI-based analysis algorithm incorporating nanoscale structural variations and measurement-angle misalignment in spectroscopic ellipsometry
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