查找使用阿拉丁产品的科研文献

Advanced Integration of Glutathione-Functionalized Optical Fiber SPR Sensor for Ultra-Sensitive Detection of Lead Ions

Jiale Wang,Kunpeng Niu,Jianguo Hou,Ziyang Zhuang,Jiayi Zhu,Xinyue Jing,Ning Wang,Binyun Xia,Lei Lei

It is crucial to detect Pb2+accurately and rapidly. This work proposes an ultra-sensitive optical fiber surface plasmon resonance (SPR) sensor functionalized with glutathione (GSH) for label-free detection of the ultra-low Pb2+concentration, in which the refractive index (RI) sensitivity of the multimode-singlemode-multimode (MSM) hetero-core fiber is largely enhanced by the gold nanoparticles (AuNPs)/Au film coupling SPR effect. The GSH is modified on the fiber as the sensing probe to capture and identify Pb2+specifically. Its working principle is that the Pb2+chemically reacts with deprotonated carboxyl groups in GSH through ligand bonding, resulting in the formation of stable and specific chelates, inducing the variation of the local RI on the sensor surface, which in turn leads to the SPR wavelength shift in the transmission spectrum. Attributing to the AuNPs, both the Au substrates can be fully functionalized with the GSH molecules as the probes, which largely increases the number of active sites for Pb2+trapping. Combined with the SPR effect, the sensor achieves a sensitivity of 2.32 × 1011nm/M and a limit of detection (LOD) of 0.43 pM. It also demonstrates exceptional specificity, stability, and reproducibility, making it suitable for various applications in water pollution, biomedicine, and food safety.Keywords:optical fiber;surface plasmon resonance;glutathione;Pb2+detection;gold nanoparticles

Sensitivity-enhanced plasmonic sensor modified with ZIF-8

Yanpei Xu,Yutong Song,Haixing Hao,Zhimeng Zhao,Yong Jin,Qi Wang

ZIF-8 is a typical metal–organic framework (MOF) material, which has great potential for sensor improvement. In this paper, we prepared a high sensitivity surface plasmon resonance (SPR) sensor based on ZIF-8/Au and described the preparation process of the sensor and characterized the samples in detail. The results showed that the synthesized ZIF-8 nanoparticles were uniform with an average diameter of about 50 nm. The performance of the sensor was related to the amount of ZIF-8, which could be controlled by adjusting the number of spin-coating cycles. When the refractive index ranged from 1.3335 to 1.3635, the maximum sensitivity of the sensor reached 3961.36nm/RIU with one cycle of spin-coating, which was 74.05% higher than that of pure Au single-layer film sensor. Furthermore, the feasibility of the proposed sensor for biological sensing was demonstrated by detecting bovine serum albumin (BSA).

Surface plasmon resonance (SPR)-enhanced photocatalytic degradation by periodically ordered δ-MnO2 arrays with alkali metals doping

Han Liu,Mingsong Zhang,Xiaoyun Liu,Zhihao Chai,Mai Li,Chunrui Wang,Jiale Wang

Periodically ordered δ-MnO 2 arrays of different periods have been fabricated by using polystyrene (PS) nanosphere lithography (NSL) combined with following hydrothermal growth. By choosing different precursors, δ-MnO 2 arrays with different alkali metals doping were obtained. It was observed that the K-doped δ-MnO 2 array of 500 nm period exhibited superior photocatalytic degradation performance of methylene blue (MB) under visible light irradiation relative to those of Na- or Mg-doped δ-MnO 2 arrays of 500 nm period, as well as K-doped δ-MnO 2 array of 800 nm period. The best performance of K-doped δ-MnO 2 array of 500 nm period can be firstly attributed to enhanced surface plasmon resonance (SPR) effect caused by alkali metal doping, where K-doped MnO 2 could provide more free electrons than those of Na- or Mg- doped MnO 2 . Furthermore, for the nanomaterials with SPR effect the surface plasmon polaritons (SPP) can change the propagation path of incident light to vertical direction after scattering on them. Since the MnO 2 array of 500 nm period possessed the distance between neighbor unites smaller than the wavelength of irradiation light, and thus the scattered light interfered with each other after the incident light was scattered by the MnO 2 unites. Then the electric field (E-field) intensities generated by SPR effect near each MnO 2 unit were elevated due to the interference effect. Therefore, our finding may provide a peculiar way to improve SPR-mediated photocatalytic performance of non-metallic materials by combination of doping and arrays fabrication of particular periods.

Ultra-sensitive optical fiber SPR Cu2+sensor enhanced by a multilayers Schiff base-hydrogel with temperature compensation

Lu-feng Wang,Ya-nan Zhang,Mao-qing Chen,Yingxuan Liu,Yong Zhao

Given the dual role of copper ions (Cu 2+ ) as essential micronutrients and harmful pollutants, the demand for developing sensitive and selective sensors capable of trace-level Cu 2+ monitoring in water bodies is urgently needed. In this paper, an ultra-sensitive surface plasmon resonance (SPR) optical fiber Cu 2+ sensor is proposed, which consists of a multimode fiber (MMF) and a 1 cm single-hole dual-core micro-structured fiber (MOF). Femtosecond laser micromachining is employed to fabricate microfluidic channel within the MOF, followed by polydimethylsiloxane (PDMS) infusion to induce an effective refractive index (RI) difference between dual cores to construct a Michelson interferometer (MI) for temperature monitoring. Simultaneously, a gold film is deposited on the MOF surface served as the SPR excitation channel, and multilayers Schiff base-functionalized hydrogel composites are immobilized onto the gold film through electrostatic layer-by-layer (LBL) self-assembly. The specific chelation between Cu 2+ with Schiff base ligands triggers hydrogel swelling, thereby inducing significant resonance wavelength shifts in the SPR spectrum. Experimental results demonstrate that the sensitivity of Cu 2+ has increased by 6 times, with the maximum sensitivity reaching −504.96 nm/(mg/L) and the limit of detection (LOD) as low as 11.0149 nM. The MI channel exclusively responds to PDMS variations due to temperature, exhibiting insensitivity to Cu 2+ concentration fluctuations, thereby eliminating the temperature cross-talk in the SPR channel. The proposed method provides a new thought for the integrated design of sensitive and specific sensors, which has great potential in food safety, environment and biology monitoring.

Temperature-compensated multiparameter SPR fiber-optic sensor for EGFR biomarker detection based on multi-mechanism signal amplification

Pengxiao Guo,Jianshe Li,Huijing Du,Kanglei Wang,Lei Zhang,Shuguang Li

Traditional surface plasmon resonance (SPR) sensors generally rely on a single sensing interface, making it difficult to achieve selective enhancement of different response mechanisms, thereby limiting their multiparameter detection capability and sensing performance. In this work, a multi-mechanism signal amplification SPR fiber-optic sensing platform based on interface-cooperative regulation is proposed for the simultaneous detection of epidermal growth factor receptor (EGFR) exon 20, pH, and temperature, while enabling real-time temperature compensation. By constructing functional interfaces with distinct physicochemical characteristics, synergistic signal amplification through multiple sensing mechanisms is achieved. Specifically, the Ag interface utilizes stable Ag–S bonding to enable efficient immobilization of probe DNA for the specific recognition of exon 20; the hydroxyl-rich Ag/TiO 2 interface facilitates the stable assembly of the PAA/CS functional layer to form a pH-responsive channel; and the Ag/MoS 2 /PDMS composite structure provides temperature monitoring and compensation through its thermosensitive characteristics. Meanwhile, the synergistic optical regulation of the high-refractive-index TiO 2 layer and the two-dimensional MoS 2 material enhances the local electromagnetic field and enables effective spectral separation among multiple sensing channels, resulting in improved sensing performance. Experimental results demonstrate average sensitivities of 0.178 nm/nM, −22.59 nm/pH, and −4.439 nm/°C for exon 20, pH, and temperature detection, respectively. By introducing a real-time temperature compensation strategy, the accuracy and reliability of EGFR exon 20 detection are further improved. The proposed sensing platform provides a promising approach for lung cancer biomarker analysis and multimodal physiological monitoring in complex biological environments.

Metal-organic frameworks/graphene oxide synergistic enhanced optical fiber SPR sensor for ultra-trace lead ions detection

Lixia Li,Yurui Huang,Siyuan Wu,Mingdeng Jin,Jiabin Zhao,Feiyou Liu,Yiyang Shen,Ning Feng,Yufang Liu

The detection of lead ions (Pb 2+ ) is critical due to its harmful effects to human health, even in trace amounts. In this paper, a novel optical fiber surface plasmon resonance (SPR) sensor for ultra-trace detection of Pb 2+ is proposed. The sensing probe consists of a metal-organic frameworks (MOF)/graphene oxide (GO) composite sensitized layer modified on the gold (Au)-based optical fiber. In the presence of Pb 2+ , DNAzyme specifically recognizes Pb 2+ and cleaves the substrate strand, resulting in the detachment of gold nanoparticles (AuNPs) conjugated to the substrate from the sensing region, which reduces the surface refractive index (RI) and thus causes a spectral blue shift. The optical fiber SPR sensor exhibits exceptional sensing performance, featuring a RI sensitivity of 4248.64 nm/RIU, achieving detection of Pb 2+ with a limit of detection of 3.419 pM. The synergistic effect of MOF and GO enlarges the specific surface area of the bound biochemical molecules and improves the electron transport rate, offering the possibility of high-performance sensing. Furthermore, the sensor we proposed exhibits excellent specificity and stability, possessing significant research potential, as well as providing a foundation for experimental exploration into high performance optical fiber sensing devices.

Label-free SPR fiber microfluidic sensor with PDA-MA cross-linked lipase for specific detection of tributyrin

Hongxin Zhang,Xuegang Li,Xue Zhou,Yanan Zhang,Yong Zhao

As a precursor to butyric acid and also a short-chain triglyceride, tributyrin plays an important role in repairing small intestinal villi, promoting the absorption and utilization of nutrients, and monitoring human health. The traditional carboxylation functionalization method of optical fiber sensors takes a long time and is complicated to operate. Therefore, we need a sensor with a functional period, high sensitivity, and the ability to quickly detect samples to achieve specific detection of tributyrin. In this paper, based on the chemical cross-linking method of polydopamine-maleic acid (PDA-MA), a novel fiber-optic microfluidic surface plasmon resonance (SPR) sensor was proposed to realize the detection of tributyrin. Compared with the traditional functionalization method, the fixation method of PDA-MA chemical cross-linking method not only shortens the functionalization time, but also increases the sensitivity of the sensor. Experimental results show that the sensitivity of the microfluidic sensor coated with PDA reaches 3392.7 nm/RIU, which is 1.75 times that of the uncoated sensor. The sensor has a sensitivity of 8.22 nm/mM in the range of 0.5–5 mM and a response time of only 8 min at the concentration of 1 mM. In addition, the sample detection error of the sensor is within 12 % in the range of 0.5–5 mM. The proposed sensor offers the advantages of low sample consumption (100 μL), high sensitivity, good selectivity, good repeatability, anti-interference ability, and label-free measurement. The sensor holds promising applications in food safety and health monitoring due to its superior performance.

Spectrally-selective SPR fiber-optic sensor for simultaneous monitoring of glucose, pH, and temperature in biopharmaceutical processes

Pengxiao Guo,Kanglei Wang,Huijing Du,Lei Zhang,Jianshe Li,Li Huo,Shuguang Li

In order to meet the requirements of real-time control of multiple parameters in biopharmaceutical processes, this paper proposes an SPR fiber optic sensor with spectral selectivity for simultaneous measurement of glucose concentration, pH value, and temperature. The sensor is a triple cascade structure, with an Ag film used to measure glucose concentration, PAA/CS self-assembly is performed on the Ag/TiO 2 surface for measuring pH, and Ag/MoS 2 /PDMS is used for measuring temperature. The innovation of this paper lies in utilizing the different optical properties of TiO 2 and MoS 2 and the response differences of functional films to different measured parameters, to endow the three-sensor band spectral selectivity, and achieve distinguishable and non-interfering synchronous responses of three parameters within the full spectrum (400–1700 nm). The experimental results showed that the sensitivity of sugar content (0–35 %) and temperature (−10–100 °C) were 5.29 nm/% and 6.8 nm/°C, respectively. At the same time, pH could be accurately measured in the range of 3.22–10.12, with detection limits of 0.151 %, 0.117 °C, and 0.043 pH, respectively, demonstrating good stability and covering the key range of typical fermentation processes. The functional film design and spectral selection mechanism proposed in this study have great potential for application in precisely grasping key parameters in biological fermentation and pharmaceuticals, and provide a new paradigm for the structural integration of multi-parameter sensors.

Strategy of Dimercaptothiol as Self-assembled Monolayers Enhance the Sensitivity of SPR Immunosensor for Detection of Salbutamol

Wenjie LI,Chenchen WANG,Huidong LI,Zilei CHEN,Mengmeng YAN

The formation of self-assembled monolayers (SAMs) is a normal method for the immobilization of biorecognition elements immobilized on SPR sensors. With this method, mercaptopropionic acid (MPA) with carboxylic and thiol group is the most commonly used. Dimercaptosuccinic acid (DMSA) having two carboxylics and two thiol groups is a classical antidote for heavy metal ions. In this paper, DMSA was first used to form SAMs to connect the antigen on the chip of a surface plasmon resonance (SPR) immunosensor for detection of salbutamol (SAL), and the results were compared with a traditional (MPA)-SPR sensor. Dihydrolipoic acid(DHLA)-SPR showed that the recognition efficiency of antigen and antibody of DMSA-SPR immunosensor was 170.1% at room temperature with the linear range of 5 – 150 ng/mL. The recovery rate of this sensor applied to SAL detection in pork reached 94.9 – 108.0% and the limit of quantification (LOQ) was 5 ng/mL. The results were in good correlation with the analysis results of ultra-high phase liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) analysis. This novel DMSA-SPR immunosensor provides insight into a new idea and method for improving the sensitivity of SPR immunosensors and can be widely used in the detection of other small molecules.

Enhanced Sum Frequency Generation for Monolayers on Au Relative to Silica: Local Field Factors and SPR Effect

Bolin Li,Yonghao Ma,Xiaofeng Han,Pengcheng Hu,Xiaolin Lu

Using metals as signal magnified substrates, surface plasmon-enhanced sum frequency generation (SFG) vibrational spectroscopy is a promising technique to probe weak molecular-level signals at surfaces and interfaces. In this study, the vibrational signals of the n-alkane monolayer on the gold (Au) and silica substrates are investigated using the broadband femtosecond SFG. The enhancement factors are discovered to be up to ∼1076 and ∼31 for the methyl symmetric and asymmetric stretching (ss and as) modes of the monolayer, respectively. By systematically analyzing the second-order nonlinear susceptibility tensor components (χijks), the Fresnel coefficients (Fijks), and the surface plasmon resonance (SPR) effect, we find that the interplay between Fijk and χijk terms and the SPR effect dominate the SFG signal enhancement. Our study reveals that the relative contributions of different influencing factors (i.e., Fresnel coefficients and SPR) to the SFG signal enhancement provide an approach to interpreting enhanced SFG vibrational signals detected from probe molecules on distinct substrates and may finally guide the design of the experimental methodology to improve the detection sensitivity and signal-to-noise ratio.

Highly Sensitive and Selective Detection of Cortisol Using a Novel SPR-Aptamer Sensor Modified by Gold Nanoparticles

Liyun Ding,Shenghu Wei,Tian Wu,Yumei Zhang,Fei Ma,Jue Zhao,Xingdong Jiang,Juanjuan Zuo

An in-fiber sensor for simultaneous measurement of cholesterol concentration and temperature based on SPR and MMI

Wanlu Zheng,Bo Han,Ya-nan Zhang,Lijun Liu,Yong Zhao

In this paper, we design an in-fiber two-parameter sensor with multimode fiber (MMF)-Au film coated hollow fiber (HCF)-MMF structure, which can simultaneously excite Surface Plasmon Resonance (SPR) effect and Multimode Interference (MMI) effect. A composite material of Au nanoparticles/β-cyclodextrin (AuNPs/β-CD) is deposited on the surface of the Au film coated HCF to realize highly-sensitive measurement of cholesterol concentration. Here, the AuNPs can not only enhance the measurement sensitivity of the SPR sensor, but also increase the numbers of combination sites of β-CD and cholesterol. Then, to solve the cross-sensitivity problem between temperature and cholesterol, the glycerin is selected as a temperature-sensitive material to fill into the inner channel of the HCF, making the MMI sensor sensitive to temperature, and finally realizing the simultaneous measurement of cholesterol concentration and temperature. The experimental results demonstrate that the wavelength shift of the SPR and the MMI are 12.7 nm and 7.9 nm, respectively, when the cholesterol concentration changes from 0 to 500 nM. The temperature sensitivity of the SPR and the MMI are −0.9 nm/°C and 2.64 nm/°C, respectively, in the temperature range of 30°C–46 °C. In addition, the sensor shows good recognition ability of cholesterol molecules in serum environment, with good stability, selectivity and repeatability, and has broad application prospects in the biomedical field.