Fiber Optic Surface Plasmon Resonance Sensor Research Articles

Polarization-independent tilted fiber Bragg grating surface plasmon resonance sensor based on spectrum optimization.

We experimentally demonstrated polarization multiplexing schemes in a tilted fiber grating (TFBG) to achieve polarization-independent fiber-optic surface plasmon resonance (SPR) sensors. The first used two orthogonal polarized lights separated by a polarization beam splitter (PBS) that are p-polarized in polarization-maintaining fiber (PMF) and precisely aligned with the tilted grating plane, so as to achieve the transmission of p-polarized light in two opposite directions of the Au-coated TFBG to excite SPR. Alternatively, polarization multiplexing was also achieved by exploring two polarization components to achieve the SPR effect through a Faraday rotator mirror (FRM). The SPR reflection spectra are polarization-independent of the light source and any perturbations to fibers, which are explained by the superposition of p- and s-polarized transmission spectra in equal proportions. The spectrum optimization is presented to reduce the proportion of the s-polarization component. A polarization-independent TFBG-based SPR refractive index (RI) sensor with a wavelength sensitivity of 555.14 nm/RIU and an amplitude sensitivity of 1724.92 dB/RIU for small changes is obtained, exhibiting unique advantages of minimizing the polarization alterations by mechanical perturbations.

An axisymmetric metal and metal-oxide grating-structured self-reference fiber optic SPR sensor

An optical-fiber-based surface plasmon resonance (SPR) sensing probe consisting of axisymmetrical grating is proposed and studied theoretically for the detection of the refractive index (RI). The sensing probe is formed by depositing a plasmonic metal layer on a bare core of optical fiber, followed by an axisymmetric grating layer and an analyte. The grating consists of metal and metal oxide in an alternate manner. The proposed structure of a single channel provides two resonance modes in the transmission SPR spectra. It is found that the mode present at the lower wavelength remains fixed, and the mode present at the higher wavelength is varied when the RI of the analyte is varied, so that the previous one works as a reference mode while the latter one works as a sensing mode. These properties provide the self-referencing capability of the proposed RI sensor in ambient conditions. We have calculated the sensitivity, detection accuracy (DA) and signal to width ratio (SWR) using the SPR spectra of various probes of different combinations of plasmonic metal and metal-oxide gratings to enhance the study. The best performing probe is found to be Ag/Cu-ITO. This optimum probe attained a maximum SWR of 42, sensitivity of 5400 nm RIU−1 and DA of 0.08 nm−1 with the self-referencing capability. The optimum probe also works well for a dispersive analyte within the spectral range. The use of metal oxide provides better adsorption of the analyte as well as high sensitivity. The cumulative properties of self-referencing and the metal oxide of the designed probe make it accurate and useful for the detection of biological elements in the ambient atmosphere.

A Field-Enhancement Optical Fiber SPR Sensor Using Graphene, Molybdenum Disulfide, and Zinc Oxide

Graphene, molybdenum disulfide (MoS $$_2$$ ), and zinc oxide (ZnO) are proposed here to enhance the evanescent field of an optical fiber surface plasmon resonance (SPR) sensor. Gold and silver are the plasmonic materials, and the fiber core material is made of polymethylmethacrylate (PMMA). A Fresnel equations-based analysis is used, and the obtained results pointed out higher values of sensitivity, figure of merit, and FWHM (full-width at half maximum) when compared to conventional SPR sensors. In despite of silver-only based SPR sensor has a better performance, oxidation occurs, and the sensor’s lifetime is reduced. The addition of graphene layers leads to sensitivity values $$50\%$$ higher than the conventional sensor. On the other hand, the MoS $$_2$$ -based sensor improves the interaction of the sensor with the bio-recognition molecules, which is attractive for biomedical applications. When ZnO was added to the silver-based sensor, a highest sensitivity, 4740.9 nm/RIU, was obtained. Graphene-based silver SPR exhibit the highest FOM values.

Integrated Signal Amplification on a Fiber Optic SPR Sensor Using Duplexed Aptamers.

Throughout the past decades, fiber optic surface plasmon resonance (FO-SPR)-based biosensors have proven to be powerful tools for both the characterization of biomolecular interactions and target detection. However, as FO-SPR signals are generally related to the mass that binds to the sensor surface, multistep processes and external reagents are often required to obtain significant signals for low molecular weight targets. This increases the time, cost, and complexity of the respective bioassays and hinders continuous measurements. To overcome these requirements, in this work, cis-duplexed aptamers (DAs) were implemented on FO-SPR sensors, which underwent a conformational change upon target binding. This induced a spatial redistribution of gold nanoparticles (AuNPs) upon specific target binding and resulted in an amplified and concentration-dependent signal. Importantly, the AuNPs were covalently conjugated to the sensor, so the principle does not rely on multistep processes or external reagents. To implement this concept, first, the thickness of the gold fiber coating was adapted to match the resonance conditions of the surface plasmons present on the FO-SPR sensors with those on the AuNPs. As a result, the signal obtained due to the spatial redistribution of the AuNPs was amplified by a factor of 3 compared to the most commonly used thickness. Subsequently, the cis-DAs were successfully implemented on the FO-SPR sensors, and it was demonstrated that the DA-based FO-SPR sensors could specifically and quantitatively detect an ssDNA target with a detection limit of 230 nM. Furthermore, the redistribution of the AuNPs was proven to be reversible, which is an important prerequisite for continuous measurements. Altogether, the established DA-based FO-SPR bioassay holds much promise for the detection of low molecular weight targets in the future and opens up possibilities for FO-SPR-based continuous biosensing.

Theoretical Design of Broadband Tunable Nanograting-Coupled Fiber-Optic Surface Plasmon Resonance For Advanced Sensing

Fiber-optic surface plasmon resonance (FOSPR) technology has drawn considerable attention to the label-free biosensing field. Currently, all FOSPR sensing devices capitalizing on flat plasmonic film are only performed on the fiber sidewalls, and demonstrated in a limited wavelength range, which is unfavorable to broaden their practical sensing application. Here, we develop and theoretically demonstrate an effective alternative for the realization of SPR on a flat gold film achieved on the end facet of optical fiber through the diffracting coupling of nanograting. This enables the consecutively adjustment of operating wavelength over a broad spectral range from visible (650 nm) to near-infrared light (1550 nm) through modulating the nanograting period. The sensing performances of the proposed nanograting-coupled FOSPR sensors with different specified resonance wavelengths are numerically investigated from two aspects of bulk refractive index and surface sensitivities. As a result, the highest bulk refractive index sensitivity of 1163 nm/RIU is obtained at the operating wavelength of 1550 nm and the optimal surface sensitivity is dependent on the location away from top surface of structure. The dependence of incident polarization direction on the sensing performances of the proposed structure are also explored. Due to the ease of adjustment of operating wavelength and compact integration on the end facet, this sensing platform can further extend the utility of FOSPR sensing technology in the practical application fields of disease diagnosis, environment monitoring, etc.

Research Advances on Fiber-Optic SPR Sensors with Temperature Self-Compensation.

The fiber-optic surface plasmon resonance sensor has very promising applications in environmental monitoring, biochemical sensing, and medical diagnosis, due to the superiority of high sensitivity and novel label-free microstructure. However, the influence of ambient temperature is inevitable in practical sensing applications, and even the higher the sensitivity, the greater the influence. Therefore, how to eliminate temperature interference in the sensing process has become one of the hot issues of this research field in recent years, and some accomplishments have been achieved. This paper mainly reviews the research results on temperature self-compensating fiber-optic surface plasmon sensors. Firstly, it introduces the mechanism of a temperature self-compensating fiber-optic surface plasmon resonance sensor. Then, the latest development of temperature self-compensated sensor is reviewed from the perspective of various fiber-optic sensing structures. Finally, this paper discusses the most recent applications and development prospects of temperature self-compensated fiber-optic surface plasmon resonance sensors.

Copper-multiwalled carbon nanotubes decorated fiber-optic surface plasmon resonance sensor for detection of trace hydrogen sulfide gas

A fiber-optic surface plasmon resonance (SPR) hydrogen sulfide (H2S) gas sensor is proposed and fabricated by using silver/triaminopropyltriethoxysilane/copper-multiwalled carbon nanotubes (Ag/APTES/Cu-MWCNT) as sensing film. A single-mode fiber (SMF) is spliced between two multimode fibers (MMF) to form an MMF-SMF-MMF sensing structure. The Ag/APTES/Cu-MWCNT sensing film is coated on the surface of SMF. The performance and stability of the sensor were investigated in detail. With the increase of H2S concentration in the range of 10–100 ppm, the redshift of the resonance dip reaches 126.465 nm, and the logarithm of H2S concentration and the resonance dip wavelength shift satisfy the linear relationship. In the range of 1–10 ppm, the wavelength shifts 117.421 nm, and H2S concentration and the dip wavelength shift meet a linear relationship. The sensitivity (12.9849 nm/ppm) is obtained, the detection limit (0.146 ± 0.031 ppm) is determined, and the response time is about 28 s. The sensor has excellent selectivity, good time, humidity and temperature stability, which has potential application in the field of trace H2S gas monitoring.

Simultaneous measurement of refractive index and temperature based on a side-polish and V-groove plastic optical fiber SPR sensor.

A simple plastic optical fiber (POF) based surface plasmon resonance (SPR) sensor is proposed and demonstrated for simultaneous measurement of refractive index (RI) and temperature. The sensor consists of a series of V-grooves along the POF and a side-polish structure at the other side of the fiber. The V-groove structure can alter the SPR excitation angle and act as a mode filter, effectively enhancing the SPR effect and narrowing the SPR wavelength width. After coating a layer of thermosensitive material-polydimethylsiloxane (PDMS) film on half part of the fiber probe, a dual-parameter sensor probe is obtained for RI and temperature measurement. Experimental results show the RI sensitivity of the prepared probe can reach 1546 nm/RIU in the RI range of 1.335-1.37 RIU and the temperature sensitivity is -0.83 nm/°C in the temperature range of 20-80°C. The sensor is simple in structure and low cost, and has potential applications in the biochemical sensing fields.

Simultaneous Measurement of Ultraviolet Irradiance and Temperature by Employing Optical Fiber SPR Sensor With Ag/ZnO/PDMS Coating

It is a challenging and valuable work to design and manufacture temperature-compensated all-fiber ultraviolet (UV) sensor. In this article, we creatively use a simple and compact optical fiber sensor based on surface plasmon resonance (SPR) for simultaneous detection of UV and ambient temperature. Different coatings [Ag/polydimethylsiloxane (PDMS) and Ag/ZnO/PDMS] are used to split a length of no-core optical fiber (NCF) into two sensing regions, which generates a transmission spectrum with two distinct SPR dips. The proposed sensor achieves a temperature sensitivity of −2.542 nm/°C in the 15 °C–35 °C range and a UV sensitivity of −0.605 nm/(mW/cm2) in the range of 0–17.20 mW/cm2. The matrix established by the wavelength shift of two dips can demodulate UV and temperature changes, and provide temperature compensation for UV detection. In addition, even in surroundings of complex and changeable UV intensity and ambient temperature, the sensor shows excellent stability and repeatability, as well as great potential in UV sensing, providing a reference for the development of multiparameter optical fiber sensors.

A Near-Infrared Plasmonic Sensor Based on Wedge Fiber-Optic for Ultra-Sensitive Hg Detection

The growing number of serious diseases caused by ever-increasing heavy metal ions pollution have necessitated the use of ion sensors in healthcare and environment monitoring systems. Even with low concentrations heavy metal ions can cause significant harm, so ultra-sensitive on-site and label-free monitoring of heavy metal ions is of great importance. In this work, a simple, portable and high sensitivity optical fiber surface plasmon resonance (SPR) sensor is demonstrated for the detection of Hg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> . On the basis of the investigation of the effects of different incident angles, the optical fiber sensor adopts wedged tip probe with a 75° incident angle. The plasmonic sensor exhibits a superior refractive index bulk sensitivity of up to 13830 nm/RIU in near-infrared band, which is a further step in ultrasensitive sensing detection, compared with the traditional optical fiber SPR sensors. In addition, we validate the optical fiber sensor's performance for Hg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> sensing. By self-assembling monolayer of 1,6-Hexanedithiol (HDT) on the sensing surface, the Au-coated fiber-optic probe is modified to capture Hg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> . The lowest detection limit is found to be 0.324 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf{ug}/\mathbf{mL}$</tex-math></inline-formula> for the near-infrared band and the sensitivity can reach up to 0.22 nm/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$({\mathbf{ug}/\mathbf{mL}})$</tex-math></inline-formula> . The experimental results show the excellent promise for our sensor in applications of environmental monitoring due to high sensitivity, selectivity and low-cost.

Ion-imprinted-polymer coated fiber-optic SPR sensor for detection of trace Cr3+ in water

A fiber-optic surface plasmon resonance (SPR) sensor based on the trivalent chromium-ion imprinted polymer (Cr3+-IIP) was proposed and fabricated. A small core-diameter fiber (SCF) with a length of 1 cm is spliced between two multimode fibers (MMFs) to form the MMF-SCF-MMF sensing structure. A 67-nm thick Ag film was evaporated on the outside surface of the SCF, and then Cr3+-IIP and nonionic imprinted polymer materials were respectively coated on the surface of the Ag film and then the fiber-optic SPR sensor was obtained. The results show that with the increase of Cr3+ concentration in the range of 0–1.1 µM, the SPR peak indicates redshift with 80.5 nm. The sensitivity and linearity of the sensor are 71.7 nm/µM and 0.994, respectively. The limit of detection of the sensor is about 0.041 μM (2.145 ppb). The fiber-optic SPR sensor is expected to be applied to the detection of trace Cr3+ ions in water.

A Dual-Parameter Optical Fiber SPR Sensor for Simultaneous Measurement of Glucose and Cholesterol Concentrations

A surface plasmon resonance (SPR) dual-parameter sensor is designed and fabricated. It was electroless plated with silver on the surface of the core of the plastic-clad optical fiber and a gold film was plated near the end face side to produce the double SPR resonance valleys. 4-mercaptophenylboronic acid (4-MPBA) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -cyclodextrin ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD) were coated separately on the surface of the silver and gold films. 4-MPBA can selectively recognize the structures of cis-vicinal diols, and thus can capture glucose that contains such structures. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD is a class of cyclic oligosaccharides whose unique hydrophilic outer surface and lipophilic central cavity help facilitate the formation of inclusion complexes with cholesterol through multiple interactions. The sensor can detect 0–4 mM glucose and 0–500 nM cholesterol, and it has a linear response in the concentration range of 0–0.1 mM glucose and 0–15 nM cholesterol. The sensitivity of glucose and cholesterol concentration of the sensor is 89.6 and 0.994 nm/nM, respectively. The detection limits for quantifying glucose and cholesterol are <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.12~\mu \text{M}$ </tex-math></inline-formula> and 0.1 nM, respectively. The experimental results also show that the sensor has good selectivity and stability. The proposed technique can be further applied in medicine, environment, and biology monitoring.

Dual-channel fiber-optic surface plasmon resonance sensor with cascaded coaxial dual-waveguide D-type structure and microsphere structure

To address the restriction of fiber-optic surface plasmon resonance (SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-type structure and microsphere structure is proposed in this paper. The fiber sidepolishing technique converts the coaxial dual-waveguide fiber into a D-type one, and the evanescent wave in the ring core leaks, generating a D-type sensing region; the fiber optic fused ball push technology converts the coaxial dual waveguides into microspheres, and the stimulated cladding mode evanescent wave leaks, producing the microsphere sensing region. By injecting light into the coaxial dual-waveguide middle core alone, the sensor can realize single-stage sensing in the microsphere sensing area; it can also realize dual-channel sensing in the D-type sensing area and microsphere sensing area by injecting light into the ring core. The refractive index measurement ranges for the two channels are 1.333–1.365 and 1.375–1.405, respectively, with detection sensitivities of 981.56 nm/RIU and 4138 nm/RIU. The sensor combines wavelength division multiplexing and space division multiplexing technologies, presenting a novel research concept for multi-channel fiber SPR sensors.

Highly reproducible fiber optic surface plasmon resonance biosensors modified by CS2 for disposable immunoassays

To achieve fiber optic surface plasmon resonance (SPR) biosensors for disposable immunoassays, the following activities are required: first, to manufacture highly consistent fiber optic SPR sensors; second, to develop highly reproducible and reliable surface modification methods for the sensors; third, to establish methods of analysis and evaluation to determine the capability and reliability of biomolecular detection. In this work, we prepared microprobe-type fiber optic SPR sensors and selected highly consistent sensors according to the Pearson correlation coefficient (PCC) model. To obtain reliable surface modification, carbon disulfide (CS2) was introduced as a crosslinker to modify anti-human IgG on the surface of fiber optic SPR biosensors for the first time. After systematic improvement and optimization, the CS2-based biosensors obtained a higher human IgG sensitivity and lower human IgG detection limit than conventional (11-MUA)-based biosensors. The PCC model was employed to evaluate the consistency of the surface-functionalized biosensors, and experimental results showed that the CS2-based biosensors exhibited reliable consistency, while the (11-MUA)-based biosensors did not. Finally, the proposed CS2-based biosensors have high selectivity and work well in serum. The surface modification method and reliable and consistency evaluation model for the sensors reported in this paper can contribute to the development of disposable fiber optic SPR biosensors.

High-Sensitivity Triple-Channel Optical Fiber Surface Plasmon Resonance Sensor

Optical fiber surface plasmon resonance (SPR) sensors are widely used for refractive index (RI) sensing, thanks to their high sensitivity. However, with the increasing demand for multiple analytes detection and sensor integration, a traditional single-channel optical fiber SPR sensor is outdated. We propose and demonstrate a novel triple-channel optical fiber SPR sensor with high sensitivity. The sensor is fabricated with side-polished single-mode fiber (SMF), where the sensing film consists of a layer of gold nanofilm and a layer of TiO2 nanofilm. The resonance wavelength range of the SPR sensing zone can be adjusted significantly by changing the TiO2 nanofilm thickness. Experimentally, by cascading three sensing zones whose TiO2 nanofilm thicknesses are 10, 30, and 60 nm, respectively, a triple-channel SPR sensor is realized. The average sensitivities of three sensing channels reach up to 2637.8, 3962.2, and 6097.3 nm/RIU in the RI range of 1.333–1.370 RIU, which is superior to most current multichannel SPR sensors. Besides, three sensing channels are independent without crosstalk. The proposed triple-channel SPR sensor has great potential in biological and chemical sensing fields, especially in multiple analytes detection applications.

D-Shaped Fiber Surface Plasmon Resonance Refractive Index Sensor Enhanced By MXene (Ti3C2Tx)

A D-shaped fiber-optic surface plasmon resonance (SPR) sensor with MXene (Ti3C2Tx) is proposed as the sensing enhancement material. A spin coating method was used to cover the gold film D-shaped fiber SPR sensor with a layer of MXene. Experimentally, the sensor's sensitivity, full width at half maximum (FWHM), and figure of merit (FOM) are discussed. The effect of various MXene concentrations on D-shaped fiber SPR sensors was investigated. The results demonstrate that as the MXene concentration increases, the sensitivity, FWHM, and FOM value of the D-shaped fiber SPR sensor increase as well. The MXene-based D-shaped fiber SPR sensor exhibits the highest sensitivity, measuring 3143 nm/RIU, and the highest FOM value, 15.26. Compared to the Au-film D-shaped fiber SPR sensor, Sensitivity is increased by 53.6%. The results indicate that MXene could be used to enhance the performance of SPR refractive index sensors.

Multichannel Fiber Optic SPR Sensors: Realization Methods, Application Status, and Future Prospects

AbstractFiber optic sensors based on surface plasmon resonance (SPR) have demonstrated outstanding performance in biomedical, environmental monitoring, public safety, and other aspects, which provide powerful platforms for qualitative detection and quantitative analysis of molecular interactions. Among them, multichannel fiber optic SPR sensor has become a core tool in parallel detection scenarios due to the superiorities of compensating for nonspecific binding and environmental fluctuations and implementing multianalyte determination. The realization methods of multichannel sensing revolve around fiber microstructures, enhancement by materials, and hybrid fiber. The applications of multichannel fiber optic SPR sensors are demonstrated in sensing of liquid refractive index (RI), RI and temperature, biochemical molecules, and physical parameters. This review thoroughly analyzes and compares the structure, excitation effect, sensing performance, and the advantages and disadvantages of each type of multichannel fiber optic SPR sensor. Even though there are still some challenges, such as insufficient sensing channels and difficulty in fabrication, in their advancement, efforts in multidiscipline including developing high‐performance sensitive films and innovating micro–nano fabrication processes will overcome these bottlenecks. Lastly, the future development directions of multichannel fiber optic SPR sensors from principle, structure, and material aspects are discussed.

Transition metal dichalcogenides boost the performance of optical fiber SPR sensors

We show the active role that the transition metal dichalcogenide MoS2 plays in enhancing the sensing performance of optical fiber sensors based on surface plasmon resonance (SPR). This is proved experimentally suggesting that the optical fiber SPR sensor with the MoS2 has an about 24 percent increase in the bulk refractive index sensitivity compared to the one without the MoS2. Also, we investigate the surface sensing performance of the sensor using self-assembly monolayers of polyelectrolytes with well-defined thickness and refractive index.

Experimental study of the copper-coated hollow fiber surface plasmon resonance sensor

A novel optical fiber surface plasmon resonance (SPR) sensor based on the copper-coated hollow fiber structure was proposed. The simple chemical liquid phase deposition method was developed to coat the thin copper film on the inner surface of the hollow fiber to fabricate the proposed sensor. The performance of the hollow fiber SPR sensors with different copper film thickness were investigated experimentally by measuring the transmission spectra of the sensors filled by sensed liquid media with different refractive indices. Theoretical analysis based on the ray transmission model was also carried out for comparison. The experimental and theoretical results agree well with each other. The factors which affect the sensor performance are discussed. The sensor achieves a maximum sensitivity of 7111 nm/RIU, which is relatively high in the copper film based optical fiber SPR sensors and comparable to the silver-coated hollow fiber sensors. Moreover, the fabrication process of the proposed sensor is much simpler than other copper based optical fiber SPR sensors, which make it more practical. The copper film deposition method presented in this paper is also applicable to the fabrication of some microstructured optical fiber or photonic crystal fiber based sensors with copper film.

Fiber Optic Plasmonic Sensors Based on Nanodome Arrays with Nanogaps.

In this study, a high-performance fiber optic surface plasmon resonance (FO-SPR) sensor using a dome array with nanogaps (DANG) is proposed for label-free real-time detection of biomolecules. A novel and simple method using polymer beads enables high sensitivity by allowing hotspots with nanometer spacing between the Au dome and the surrounding film. The nanodome structure, which comprises a polymer core and a Au shell, induces a localized surface plasmon, expands the sensing area, and extensively enhances the electromagnetic field. The refractive index sensitivity of the FO-SPR sensor with nanostructures, i.e., with nanogaps and nanodomes, was found to be 7.8 times higher than that of the FO-SPR sensor without nanostructures. The proposed sensor achieved a low detection limit of 38 fg/mL while quantifying thyroglobulin antibody-antigen interactions and exhibited excellent selectivity. In addition, it helped detect serum samples with a 103% recovery rate.