plasmonic sensor
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2022 ◽  
Pibin Bing ◽  
Qing Liu ◽  
Guifang Wu ◽  
Sheng Yuan ◽  
Zhongyang Li ◽  

Abstract In this paper, a dual-core microchannel-based fiber sensor is studied by using finite element method in the visible and near-infrared bands. Plasmonic material gold (Au) is deposited in microchannel to generate the surface plasmon resonance (SPR) effect, so that sensor can detect the change in RI of its surrounding analyte. Simulation results show that the maximum wavelength sensitivity and resolution are 33600nm/RIU and 2.97×10−6RIU for y polarization in the RI range of 1.33 to 1.44, respectively. The highest figure of merit (FOM) of the sensor is 961 for y polarization. In addition, we study the effects brought by the structural changes of the fiber sensor, and the results show that the design of “microchannel coating” dramatically improves the refractive index detection ability of the sensor. The D-shaped dual-core microchannel-based photonic crystal fiber sensor proposed in this paper has a simple structure, low manufacturing complexity, and high sensitivity. Combined with external sensing technology, this sensor has great application potential in the fields of biotechnology, medical diagnosis, and environmental protection.

2022 ◽  
Lingqiao Li ◽  
Wei Cui ◽  
Zhihui He ◽  
Weiwei Xue ◽  
Hui He

Abstract Sensors for detecting glucose concentrations are crucial to medical testing. Here, we introduce silver nanoparticles (Ag NPs) uniformly distributed in space to investigate the sensing properties for detecting glucose by using the finite-different time-domain (FDTD) and experimental methods. The results show that the transmittance of dip for the proposed structural model gradually decreases as the number of Ag NPs increases, when the concentration of glucose is constant. And the transmission spectrum shows slight red shift with the increasing of the glucose concentration. Moreover, the simulation results are in agreement with the experimental results. Especially, the maximum sensitivity S=1144.07407 nm/RIU can be realized for glucose concentration variation from 0.3 to 0.4 mol/L. The research results reveal an excellent sensing property that has important application value in medical detection.

RSC Advances ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 929-938
Ajay Kumar Agrawal ◽  
Akanksha Ninawe ◽  
Anuj Dhawan

Nanostructured plasmonic sensor chips interrogated using the Kretschmann configuration for highly sensitive localized sensing.

2021 ◽  
Vol 54 (1) ◽  
Lway Faisal Abdulrazak ◽  
Md. Biplob Hossain ◽  
Md. Shofiqul Islam ◽  
Abdulhameed Fouad Alkhateeb ◽  
Ibrahim M. Mehedi ◽  

Nunzio Cennamo ◽  
Alessandra Maria Bossi ◽  
Francesco Arcadio ◽  
Devid Maniglio ◽  
Luigi Zeni

Soft, deformable, molecularly imprinted nanoparticles (nanoMIPs) were combined to nano-plasmonic sensor chips realized on poly (methyl methacrylate) (PMMA) substrates to develop highly sensitive bio/chemical sensors. NanoMIPs (dmean < 50 nm), which are tailor-made nanoreceptors prepared by a template assisted synthesis, were made selective to bind Bovine Serum Albumin (BSA), and were herein used to functionalize gold optical nanostructures placed on a PMMA substrate, this latter acting as a slab waveguide. We compared nanoMIP-functionalized non-optimized gold nanogratings based on periodic nano-stripes to optimized nanogratings with a deposited ultra-thin MIP layer (<100 nm). The sensors performances were tested by the detection of BSA using the same setup, in which both chips were considered as slab waveguides, with the periodic nano-stripes allocated in a longitudinal orientation with respect to the direction of the input light. Result demonstrated the nanoMIP-non optimized nanogratings showed superior performance with respect to the ultra-thin MIP-optimized nanogratings. The peculiar deformable character of the nano-MIPs enabled to significantly enhance the limit of detection (LOD) of the plasmonic bio/sensor, allowing the detection of the low femtomolar concentration of analyte (LOD ∼ 3 fM), thus outpassing of four orders of magnitude the sensitivies achieved so far on optimized nano-patterned plasmonic platforms functionalized with ultra-thin MIP layers. Thus, deformable nanoMIPs onto non-optimized plasmonic probes permit to attain ultralow detections, down to the quasi-single molecule. As a general consideration, the combination of more plasmonic transducers to different kinds of MIP receptors is discussed as a mean to attain the detection range for the selected application field.

Chemosensors ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 363
Semra Akgönüllü ◽  
Handan Yavuz ◽  
Adil Denizli

Aflatoxins are a group of extremely toxic and carcinogenic substances generated by the mold of the genus Aspergillus that contaminate agricultural products. When dairy cows ingest aflatoxin B1 (AFB1)−contaminated feeds, it is metabolized and transformed in the liver into a carcinogenic major form of aflatoxin M1 (AFM1), which is eliminated through the milk. The detection of AFM1 in milk is very important to be able to guarantee food safety and quality. In recent years, sensors have emerged as a quick, low–cost, and reliable platform for the detection of aflatoxins. Plasmonic sensors with molecularly imprinted polymers (MIPs) can be interesting alternatives for the determination of AFM1. In this work, we designed a molecularly–imprinted–based plasmonic sensor to directly detect lower amounts of AFM1 in raw milk samples. For this purpose, we prepared gold–nanoparticle–(AuNP)−integrated polymer nanofilm on a gold plasmonic sensor chip coated with allyl mercaptan. N−methacryloyl−l−phenylalanine (MAPA) was chosen as a functional monomer. The MIP nanofilm was prepared using the light–initiated polymerization of MAPA and ethylene glycol dimethacrylate in the presence of AFM1 as a template molecule. The developed method enabled the detection of AFM1 with a detection limit of 0.4 pg/mL and demonstrated good linearity (0.0003 ng/mL–20.0 ng/mL) under optimized experimental conditions. The AFM1 determination was performed in random dairy farmer milk samples. Using the analogous mycotoxins, it was also demonstrated that the plasmonic sensor platforms were specific to the detection of AFM1.

2021 ◽  
Bahar Meshginqalam ◽  
Jamal Barvestani

Abstract A highly sensitive D-shaped photonic crystal fiber sensor with circular lattice is proposed for external plasmonic sensing. The proposed design of plasmonic material in a D-shaped form effectively facilitates the excitation of surface plasmons and enhances the sensor performance. As a comparative study, two different plasmonic materials, gold and silver, are applied D-shapely on the fiber and the proposed sensor performance is numerically investigated and evaluated. Moreover, the optimized structural parameters such as air-hole diameters and the thickness of silver and gold layers are selected via simulation results which cause the highest sensitivity of 40000nm/RIU for the gold coated fiber using the wavelength interrogation method. Furthermore, the maximum figure of merit can reach 621.50RIU-1. Analytes with the refractive indices ranging from 1.34 to 1.39 can be detected by double-loss peak that is a more reliable method of simultaneous detection and verification of sensing characteristics. Due to its promising results, the proposed sensor can be widely useful in the area of chemical and biological sensing.

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