SENSORS
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2018
·Vol. 18
·期 10
·3458
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IF 2.475
Chao Zhuang,Yifan Xu,Ningsheng Xu,Jinxiu Wen,Huanjun Chen,Shaozhi Deng
Plasmonic gold nanorods play important roles in nowadays state-of-the-art plasmonic sensing techniques. Most of the previous studies and applications focused on gold nanorods with relatively small aspect ratios, where the plasmon wavelengths are smaller than 900 nm. Gold nanorods with large aspect ratios are predicted to exhibit high refractive-index sensitivity (Langmir 2008, 24, 5233–5237), which therefore should be promising for the development of high-performance plasmonic chemical- and bio-sensors. In this study, we developed gold nanorods with aspect ratios over 7.9, which exhibit plasmon resonances around 1064 nm. The refractive index (RI) sensitivity of these nanorods have been evaluated by varying their dielectric environment, whereby a sensitivity as high as 473 nm/RIU (refractive index unit) can be obtained. Furthermore, we have demonstrated the large-aspect-ratio nanorods as efficient substrate for surface enhanced Raman spectroscopy (SERS), where an enhancement factor (EF) as high as 9.47 × 108was measured using 4-methylbenzenethiol (4-MBT) as probe molecule. Finally, a type of flexible SERS substrate is developed by conjugating the gold nanorods with the polystyrene (PS) polymer. The results obtained in our study can benefit the development of plasmonic sensing techniques utilized in the near-infrared spectral region.Keywords:large aspect ratios;gold nanorods;refractive index sensitivities;SERS;plasmonic sensing
研究领域:
纳米技术
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光学
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化学传感器
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生物医学工程
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DOI
PubMed
高影响因子
Nanoscience and Nanotechnology Letters
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2018
·Vol. 10
·期 3
·346-350
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IF 2.917
Zhao Hongyan,Liu Xin,Zhang Shoubao,Liu Xiaoli,Ma Rende,Zhou Shaoshuai,Han Shuo,Shen Chuanying,Wang Chao
By using the finite difference time domain method, the localized surface plasmon extinction spectrum of different sizes of spherical gold and silver nanoparticles were simulated and analyzed in external environments with various refractive indices. It was observed that the changes in
the position of the resonance wavelength were linearly proportional to the external refractive index, while the sensitivity increased with nanoparticle size. The sensitivity of the spherical silver nanoparticles with a radius of 40 nm reached 122 nm/RIU. For the silver and gold nanoparticles
of the same size, the sensitivity of the silver nanoparticles was greater than that of the gold nanoparticles. In the experiment, the spectral characteristics of the silver nanoparticles with different sizes under various external refractive indices were measured. The experimental results
were consistent with the simulation results. The resonance wavelength and the concentration of the solution showed a good linear relationship. By using the sensitive properties of the nanoparticles such as external refractive index, the amount of sucrose in the solution can be measured.
研究领域:
光学
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纳米科技
✓ 已验证
DOI
高影响因子
MEASUREMENT
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2023
·
IF 5.6
Xuegang Li,Hongxin Zhang,Yiming Wang,Xue Zhou,Linh Viet Nguyen,Stephen C. Warren-Smith
An optofluidic DNA biosensor based on a suspended core fiber (SCF) has been proposed for the detection of specific DNA sequence fragments. The sensor is formed by coupling a micro/nano tapered optical fiber to the cladding of an SCF, producing a whispering gallery mode (WGM) effect. The WGM resonance is sensitive to samples within the channels of the SCF. The diameter of the SCF is reduced by etching to increase refractive index sensitivity, up to 274 nm/RIU. Biomarkers are captured on the inner surface of the microfluidic channel leading to a change in the local refractive index. The experimental results show that the sensor can quantitatively detect complementary DNA (cDNA) by immobilizing probe DNA (pDNA) on the surface of the microfluidic channel with a limit of detection of 1.5 nM. The proposed DNA biosensor provides a label-free method for DNA detection, which has great potential for multiplexed detection and realizing disease diagnostics.
研究领域:
生物医学工程
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光学传感
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分子生物学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Qiang Zhang,Junlei Zhao,Anqi Han,Xiaonan Zhang,Mingya Yang,Hui Li,Benli Yu,Guosheng Zhang,Sheng Zhou
Cancer cell screening is very important for its treatment and prognosis. The screening techniques are required with high sensitivity and specific recognition. Here, an ultrasensitive tapered optical fiber (TOF) biosensor for cancer cell sensing is proposed. The unique property of the dispersion turning point (DTP) in the TOF is utilized to greatly improve the sensing sensitivity. Combined with numerical calculations, the TOF with the extremely high refractive index (RI) sensitivity (close to 18390 nm/RIU) near the DTP is achieved by precisely controlling the diameter of the TOF. In addition, biotin is used to functionalize the TOF for specific recognition of the biotin-overexpressing cancer cells. The sensitivity and selectivity of the TOF were demonstrated by the detection of the biotin receptor protein (streptavidin) and overexpressed cancer cells (lung epithelial adenocarcinoma cells, A549). The experiment results show that the TOF has a low limit of detection (LOD) for streptavidin and cancer cells, which are 28.73 pM and 49 cells/mL respectively. At the same time, the TOF showed the obvious response to another biotin-overexpressed cancer cell (breast cancer cells, 4T1), but is insensitive to normal cells (gastric mucosa cells, GES-1 and mouse epithelioid fibroblasts cells, L929). We believe that the proposed biosensor which exhibited extremely high sensitivity and good selectivity, will have potential application prospects in the field of chemical and biological detection.
研究领域:
生物医学工程
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光学传感
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癌症检测
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
·
IF 8
Zhaoyu Wang,Mingyu Li,Xin Chen,Kaihao Zhao,Jiamei Gu,Jian-Jun He,Qiu-Shun Li,Wen-Fei Dong
Silicon-based optical biosensors have garnered significant interest since their inception. They are, however, susceptible to temperature fluctuations in a controlled environment. In order to address this issue, we provide a solution including the utilization of a silicon-on-insulator (SOI) cascaded micro-ring resonators (CMRR) biosensor that is designed to be insensitive to temperature changes. It consists of two ring resonators exposed to the reference solution and analyte, respectively, their radius and waveguide width are designed to meet the temperature - insensitivity criterion of the CMRR sensor. The results of experiments indicate that by real-time monitoring of the envelope peak drift in the transmission spectrum of the sensor, the bulk refractive index (RI) sensitivity is 2940.71 nm/RIU, the limit of detection (LOD) is 3.1×10 −5 RIU, and the temperature sensitivity is less than 40 pm/℃. Furthermore, the sensor was applied for HSA detection, with a calculated LOD of 18.09 ng/mL. The effect of temperature on HSA detection is much smaller than that of a CMRR sensor without athermal design. The sensor demonstrates high sensitivity and temperature insensitivity, and the absence of negative thermo-optic coefficient materials or supplementary temperature control mechanisms simplifies its practical applications. It can be made by a large array to detect different type protein molecules for high throughput multiparameter analysis.
研究领域:
生物医学工程
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光学传感
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分子检测
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Qiang Chen,Yi Cai,Tianyu Jiang,Qing Chen,Jianhua Wang,Yong Zhao
Double-hole optical fiber (DHF) exhibits considerable potential for sensing applications due to its distinctive structural characteristics. In this study, a Sagnac interference (SI) optical fiber sensor based on a corroded DHF shows high refractive index (RI) sensitivity, allowing for the detection of copper ions, Cu(II), at very low concentrations. The dependence of DHF corrosion on the birefringence and RI sensitivity are investigated by the optical simulation. Experimental results illustrate that the RI sensitivity reaches 3267 nm/RIU within the range of 1.3333–1.3743, exhibiting good linearity. A chitosan derivative (CSD) with ion-imprinted (IIM) treatment is coated on the surface of the corroded DHF for Cu(II) detection. It is demonstrated that within the concentration range of Cu(II) from 10 −15 to 10 −6 M, both the maximum and average sensitivities can reach 12.08 × 10 9 and 129.96 nm/μM, respectively, without interference from other metal ions or temperature (25.3–44.0 ℃). The proposed corroded DHF sensor is a good candidate for RI and Cu(II) concentration detection due to its simple structure, high sensitivity, and selectivity.
研究领域:
光学传感
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材料科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
OPTICS COMMUNICATIONS
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2022
·
IF 2.335
Lixia Li,Linlin Zhao,Xueyang Zong,Yuli Li,Penglei Li,Yufang Liu
We show the active role that the transition metal dichalcogenide MoS 2 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 MoS 2 has an about 24 percent increase in the bulk refractive index sensitivity compared to the one without the MoS 2 . Also, we investigate the surface sensing performance of the sensor using self-assembly monolayers of polyelectrolytes with well-defined thickness and refractive index.
研究领域:
光学
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材料科学
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传感技术
✓ 已验证
产品关联
DOI
高影响因子
IEEE Transactions on Terahertz Science and Technology
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2024
·
IF 3.9
Jiaojiao Yu,Gan Liu,Xuan Zhang,Jianyuan Qin
Imidacloprid is a common insecticide which can remain in water, soil, and plant parts with long-term consumption, threaten environment and human health. Therefore, it is necessary to propose an effective method for imidacloprid detection. Here, a terahertz metamaterial based on electromagnetically induced transparency (EIT) is theoretically and experimentally demonstrated. This metamaterial displays an EIT resonance at 0.89 THz and the physical mechanism of the EIT effect is investigated by analyzing the electric fields and surface current distribution. The EIT resonance can be modulated by changing the geometric structure parameters of the metamaterial. This metamaterial can be used to detect the thickness and the refractive index of the dielectric layer based on the EIT resonance, and can achieve a refractive index sensitivity of 210 GHz/RIU. The detection of imidacloprid shows that the frequency shift and the transmittance change at peak are depend on the change of imidacloprid concentration. The minimum detectable imidacloprid concentration reaches a level of 0.01 ppm in this case. These results theoretically and experimentally prove the feasibility of terahertz metamaterial based on EIT resonance applied in the detection of imidacloprid concentration.
研究领域:
环境科学
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生物医学工程
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
Plasmonics
·
2016
·Vol. 12
·期 3
·663-673
·
IF 2.146
Lu Mengdi,Liang Yuzhang,Qian Siyu,Li Lixia,Jing Zhenguo,Masson Jean-Francois,Peng Wei
In this paper, we report a novel wavelength interrogation-based surface plasmon resonance (SPR) system, in which a film of three Ag layers and three Au layers are alternately deposited on a Kretschmann configuration as sensing element. This multilayer film shows higher sensitivity for refractive index (RI) measurement by comparing with single Au layer structure, which is consistent with its theoretical calculation. A sensitivity range of 2056–5893 nm/RIU can be achieved, which is comparable to RI sensitivities of other wavelength-modulated SPR sensors. Compared with Ag film, this Ag/Au multilayer arrangement offers anti-oxidant protection. This SPR biosensor based on a cost-effective Ag/Au multilayer structure is applicable to the real-time detection of specific interactions and dissociation of low protein concentrations. To extend the application of this highly-sensitive metal film device, we integrated this concept on an optical fiber. The range of RI sensitivities with Ag/Au multilayer was 1847–3309 nm/RIU. This miniaturized Ag/Au multilayer-based fiber optic sensor has a broad application in chemical and biological sensing.
研究领域:
生物医学工程
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光学传感
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Plasmonics
·
2021
·Vol. 17
·期 2
·597-612
·
IF 2.404
Li Jian-Jun,Qin Qiu-Xiang,Weng Guo-Jun,Zhu Jian,Zhao Jun-Wu
In this study, Au–Ag nanoboxes are converted into Au–Ag alloy nanocages by increasing the hole size. The extinction spectrum and the refractive index sensing characteristics of Au–Ag alloy nanocages with different geometric parameters are studied by using discrete dipole approximation method (DDA). With the increase of Au composition, the peak of local surface plasmon resonance (LSPR) shows approximately linear redshift and the sensitivity factor shows approximately linear decrease. The refractive index sensitivity can be effectively controlled by the Au–Ag ratio at large hole size because the hole and cavity surfaces distribute more environmental dielectric components. Therefore, increasing the hole size and decreasing the Au–Ag ratio can improve the refractive index sensitivity. These calculation results have also been verified experimentally. In order to illustrate the influence of alloy composition on the LSPR characteristics and the refractive index sensitivity, the local electric field distributions under different geometric parameters are plotted. We find that the electric field direction on the hole and cavity surfaces is controlled by the Au–Ag ratio and environmental dielectric constant. Moreover, the field vectors on the hole and cavity surfaces are formed by the superposition of the incident field, the electric field generated by the oscillating electrons on the outer surface, and the polarized field in the environmental dielectric constant.
研究领域:
纳米材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICS AND LASERS IN ENGINEERING
·
2020
·
IF 4.273
Hang Song,Qi Wang,Wan-Ming Zhao
In this work, we proposed a novel surface plasmon resonance (SPR) sensitivity-enhancing method by adding MoS 2 nanosheets between gold film and fiber (fiber-MoS 2 -gold film). And we apply it to the detection of human IgG protein. The sensor was fabricated by attaching MoS 2 nanosheets to the U-shaped fiber surface and then covering a layer of gold film. The refractive index sensitivity of 6184.4 nm/RIU was achieved by the fiber-MoS 2 -gold film sensor which is 59 percent higher than the gold film SPR sensor and 25 percent than the fiber-gold film-MoS 2 SPR sensor.The presence of MoS 2 increases the absorption of light energy and excites a stronger SPR phenomenon. At the same time, since the monolayer MoS 2 is a direct bandgap semiconductor, the absorbed light energy promotes the transfer of electrons, generates strong coupling on the gold film surface, enhances the surface electric field, and improves the sensitivity of the sensor. Biofunctionalized sensor detect human IgG with the limit of detection as low as 19.7 ng/mL. This work proposed a novel method for enhancing the sensitivity of SPR sensor, it owns a higher sensitivity and a lower LOD which has broad application prospects in measuring low concentration biological analytes.
研究领域:
光学
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生物传感
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纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
·
2023
·
IF 5.6
Liangliang Cheng,Wanlu Zheng,Ya-Nan Zhang,Xuegang Li,Yong Zhao
A highly sensitive fiber-optic urea sensor was designed and experimentally demonstrated based on surface plasmon resonance (SPR) effect and metal-organic zeolite framework (MOF), [zeolite imidazole skeleton-8 (ZIF-8)]/urease modification. The SPR effect was excited by plating gold film on the thin core fiber (TCF) in multimode-thin core-multimode fiber (MMF) structure, which behaved high refractive index sensitivity. The ZIF-8/urease composite film was grown on the gold film by rapid aqueous phase synthesis method, in which the ZIF-8 could immobilize more urease and made urease and urea fully contact. Since the urease catalyzed urea hydrolysis would change the refractive index, the measurement of urea concentration was realized with high sensitivity and good selectivity. Experimental results showed that the urea measurement sensitivity of the proposed sensor could reach 6 nm/mM within the concentration range of 1–7 mM, which has great application potential in the field of human health monitoring.
研究领域:
光学传感
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
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