查找使用阿拉丁产品的科研文献

Probe-Type High-Sensitivity DNA Hybridization Detection Based on Optical Fiber SPR

Xuegang Li,Pengqi Gong,Xue Zhou

Deoxyribonucleic acid (DNA) detection represents an important direction of diagnosis and treatment of genetic diseases, which contains all the genetic information of the human body. The DNA sequence remains extremely challenging to detect, despite numerous previous studies that have achieved selective detection, due to the backward sensing scheme. For low-cost, high-sensitivity DNA hybridization detection, a probe-type highly sensitive DNA detection method based on surface plasmon resonance (SPR) is demonstrated in this article. First, low-cost refractive index (RI) tracking detection can be completed via optical fiber SPR. Then, the selective detection of complementary DNA (cDNA) is achieved by binding the probe DNA (pDNA) sequence to the optical fiber SPR sensor using polyethyleneimine (PEI). Compared with previous studies, the sensitivity [0.13 nm/(nmol/L)] is greatly upgraded, and the detection limit (DL) is reach to 4.87 nmol/L. This low-cost and high-performance optical fiber sensing method is conducive to the further development of DNA hybridization detection technology.

Fiber-Optic SPR Biosensor With BOD/AuNPs Co-Modification for Bilirubin Detection

Kun-Yang He,Liang-Liang Cheng,Wan-Lu Zheng,Ya-Nan Zhang

A Fiber-optic surface plasmon resonance (SPR) bilirubin biosensor based on gold nanoparticles (AuNPs) and bilirubin oxidase (BOD) was proposed in this work. Leveraging the refractive index (RI) sensitivity of SPR and the specific binding capability of BOD to bilirubin, this sensor enables specific detection of bilirubin. To improve the sensitivity of bilirubin detection, AuNPs were introduced to amplify the evanescent field for optical signal enhancement while providing a high surface area for increased BOD immobilization sites. Experimental results demonstrated that the sensor achieved a sensitivity of 54.6 nm/mM within the 0–0.14 mM concentration range and a detection limit of $11.5~\mu $ M. This sensor exhibits the advantages of low sample consumption, compact size, rapid response, good stability, and high specificity. Additionally, the accurate detection of bilirubin in real serum samples demonstrates its great application potential for clinical diagnosis.

Fiber-optic SPR cholesterol sensor based on Au film- AuNPs coupling enhancement

Yi Li,Shunye Huang,Jianyang Zhang,Rongqi Zhang,Feng Xia,Xuqiang Wu,Like Li,Yong Zhao

Cholesterol is a vital biomolecule in the human body. Abnormal blood cholesterol levels may increase the risk of cardiovascular disease and Alzheimer’s disease. Therefore, there is an urgent need to develop a highly sensitive and rapid method of detecting cholesterol concentration in clinical settings. To meet this demand, we developed a reflective fiber-optic cholesterol sensor based on multimode and single-mode fibers (MMF-SMF). The probe uses AuNPs, synthesised using the sodium citrate reduction method, as a sensitising material, and cholesterol oxidase serves as the sensing membrane. This reflective optical fiber surface plasmon resonance (SPR) biosensor enables the detection of cholesterol concentration with high sensitivity. Experimental results demonstrated that Au film- AuNPs coupling enhances the refractive index sensitivity by 41.3 % to 2243.9 nm/RIU. Cholesterol detection sensitivity increases by 16.02 % to 0.210 nm/nM, and the linear detection range expands from 0–50 nM to 0–70 nM and the detection limit decreases to 4.586 nM. The sensor also exhibits excellent selectivity and stability, and can be used for the detection of cholesterol concentration in real serum samples, offering an efficient solution for developing portable biosensors.

Fiber balloon shaped SPR sensor for specific detection of Cr(VI) ions

Chunlan Liu,Zichun Zhao,Yabin Shao,Yong Wei,Ziqiang Zhang,Chao Guo,Zhihai Liu

Hexavalent chromium (Cr(VI)), as a highly toxic and carcinogenic heavy metal ion, poses a serious threat to the environment and human health. Therefore, specific detection of it is of great significance. Based on this, this article proposes a balloon shaped fiber SPR sensor with microsphere structure for specific detection of hexavalent chromium ions. The balloon structure facilitates the formation of insertable sensing probe, and the microsphere structure located on one side of the balloon structure can adjust the incidence angle of light in the sensing area to enhance the sensitivity of the sensor, resulting in a maximum refractive index sensitivity of 5068 nm/RIU. Modifying 4-mercaptoethylpyridine on the surface of the gold film of the sensor can achieve specific recognition of Cr(VI). The experimental results indicate that the balloon shaped SPR sensor with microspheres proposed in this paper has a detection limit of as low as 0.57ng/mL for Cr (VI) in the detection range of 1ng/mL-100μg/mL, with a detection time of 3 minutes, providing a new method for rapid, low concentration, and specific detection of Cr(VI).

U-shaped SPR Optical Fiber Sensor for the Detection of Acid Phosphatase

Xin Yan,Xiaobing Chen,Rao Fu,Haihui Li,Huina Tang,Yuhan Qu,Zhiyuan Yin,Tonglei Cheng,Xue Zhou

Acid phosphatase (ACP) holds significant importance in aspects related to human life and well-being. Consequently, there is a need to design a sensitive and accurate sensor. Herein, a sensitive and convenient U-shaped surface plasmon resonance (SPR) optical fiber sensor used for detecting ACP is developed. The U-shaped optical fiber sensor demonstrates remarkable sensitivity in the course of detection. A 50-nm-thick Au film was deposited on the surface of the U-bent optical fiber. When the radius of the fiber is 1 mm, the refractive index sensitivity can reach 5855 nm/RIU. Subsequently, a 20-nm-thick MnO₂ film was deposited on top of the Au film. Ascorbic acid (AA produced by ACP-catalyzed trisodium L-ascorbate-2-phosphate (AAP) can reduce MnO₂, as a result, it alters the refractive index (RI) on the surface of the optical fiber and brings about short-wavelength direction shift in the resonance wavelength. The linear detection range of this sensor is 10^-5-1 mU/mL and the limit of detection (LOD) is 9.4×10^-6 mU/mL. With the high selectivity, and high sensitivity, this sensor is utilized for the detection of ACP within human urine samples, which indicates that this sensor is promising for application in real sample.

SPR Signal Amplification Based on Dynamic Field Enhancement at the Sensor Surface

Zhe Zhang,Rumeng Yi,Shanshan He,Lin Liu,Xiangdong Guo,Ran Gao,Zhi-mei Qi

MoS2-spaced bimetal composite structure as SERS-SPR sensor for glucose detection

Baoyuan Man,Guilin Wang,Zhen Li,Shicai Xu,Chonghui Li,Jing Yu,Chao Zhang,Xiaofei Zhao

To obtain more information and reduce false alarms during molecular identification, the Molybdenum disulfide (MoS 2 ) spaced gold (Au)-silver (Ag) bimetal composite structure for surface-enhanced Raman scattering (SERS)-surface plasmon resonance (SPR) sensor is proposed. The sensor combines the advantages of D -shape plastic optical fiber ( D -POF), MoS 2 -spaced Au and Ag bimetallic composite structure, showing excellent sensitivity. Compared with the Ag/Au bimetallic D -POF experiment (the sensitivity is 2163.57 nm/RIU), the sensitivity of proposed sensor was improved effectively and calculated as 2473.37 nm/RIU in a range of alcohol solution. To evaluate the SERS activity of the proposed sensor, Rhodamine 6 G (R6G) molecules has been successfully detected by Au/MoS 2 /Ag D -POF sensor with low limited of detection (LOD) of 10 −9 M. Meanwhile, the proposed sensor successfully detected glucose with a concentration of 0.625~20% by observing the change of resonance wavelength and the characteristic peak of SERS signal. The highly sensitive spectral signals, richer and more comprehensive information can be obtained to reduce false positives in identification of biomolecules.

Dual-mode melamine detection based on gold nanoparticles aggregation-induced fluorescence “turn-on” and “turn-off” of CdTe quantum dots

Jian Zhu,Hui Chang,Jian-Jun Li,Xin Li,Jun-Wu Zhao

Both “turn-on” and “turn-off” fluorescent probe for the determination of melamine have been developed by tuning the inner filter effect (IFE) from CdTe quantum dots (QDs) to gold nanoparticles. Because of the melamine-induced aggregation of gold nanoparticles, the first absorption peak of the transverse surface plasmon resonance (SPR) at 520   nm fades down, whereas the second absorption peak of the longitudinal SPR around 620   nm gets intense. The decrease of the transverse SPR reduces the IFE of the bundled CdTe QDs with an emission band at 525   nm (the corresponding particle size is 1.98   nm), which results in the melamine concentration-dependent fluorescence recovery of CdTe QDs. The increase of the longitudinal SPR enhances the IFE of the bundled CdTe QDs with an emission band at 620   nm (the corresponding particle size is 3.68   nm), which results in the melamine concentration-dependent fluorescence decrease of CdTe QDs. The green mode detection with the fluorescence recovery has a linear response for melamine from 20 to 100   ng/mL with a theoretical detection limit of 8   ng/mL. The red mode detection with the fluorescence decrease has a linear response for melamine from 20 to 100   ng/mL with a theoretical detection limit of 11   ng/mL. Interference studies and real samples detection show that the melamine could be specifically detected using this dual-mode fluorescent probe.

Highly-sensitive and reflective glucose sensor based on optical fiber surface plasmon resonance

Wanlu Zheng,Bo Han,Siyu E,Yang Sun,Xuegang Li,Yi Cai,Ya-nan Zhang

A reflective optical sensor based on surface plasmon resonance (SPR) was proposed to measure the glucose concentration. The gold film was sputtered on the surface of plastic cladding optical fiber to excite SPR and reflect light at the same time, making the SPR sensor highly sensitive to the variation of surrounding refractive index. Then, glucose oxidase (GOD) was adopted as the sensitive film of glucose and covalently bonded on the gold film. The enzymatic reaction between the GOD and the glucose led to the change of refractive index around the optical fiber sensor, and then cause a shift of the SPR spectrum. Therefore, the glucose concentration could be obtained by monitoring the shift of the resonance wavelength. Experimental results showed that the measurement sensitivity of the SPR sensor could reach 85.4 nm/(mg/mL) (for glucose concentration) with good selectivity and stability, which has great potential application in biomedicine and human health monitoring.

High sensitive optical fiber SPR sensor for label-free detection of Staphylococcus aureus

Jiale Wang,Chao Zhao,Jiayi Zhu,Binyun Xia,Ning Wang,Xi Chen,Kunpeng Niu,Jianguo Hou,Xinyue Jing,Hang Zhou,Ziyang Zhuang,Lei Lei

Optical fiber bacterial sensors have attracted attention in many fields due to their unique advantages. However, it is still difficult to promote its practicality which is mainly subject to their low sensitivity, inferior stability, and reliability. This work reported here an optical fiber surface plasmon resonance (SPR) biosensor enhanced by gold nanoparticles (AuNPs)/Au film coupling for label-free detection the Staphylococcus aureus ( S. aureus ), while both the gold substrates were successfully biofunctionalized with goat anti-human immunoglobulin G (IgG) as the probe to capture and detect the bacteria. In the experiment, the refractive index（RI） sensitivity of the Multimode-Singlemode-Multimode optical fiber (MSMOF) coated with Au film was improved by 19 % after the AuNPs were homogeneously decorated on the Au film surface. To detect S. aureus by the sensor , the SPR wavelength variation in the transmission spectrum was recorded, and its limit of detection (LOD) was demonstrated experimentally to be about 50 CFU/mL and was obtained theoretically to be 1.18 CFU/mL during its concentration range of 50–10 8 CFU/mL. Also, it shows great linearity in the range of 10 2 -10 8 CFU/mL and the sensor exhibits excellent specificity and stability. This kind of SPR-enhanced optical fiber biosensor is fully promising for its applications in biomedicine, food safety, pharmaceuticals, etc.

Fiber SPR Sensor Based on S-Taper Sensitivity Enhancement for Nickel Ion Detection

Yong Wei,Jing Cheng,Yabin Shao,Chunlan Liu,Puxi Ren,Yixiong Tang,Ziqiang Zhang,Mingjun Cai,Zhihai Liu

Highly water-retentive thermoresponsive hydrogel-enhanced fiber spr sensor for wearable respiration monitoring

Wenxuan Gu,Chunbiao Liu,Mengqi Chen,Yu Zhang,Xuhao Ji,Zhihai Liu,Libo Yuan

A water-retentive thermoresponsive hydrogel was designed for fiber SPR sensing. • Nano clay and polyhydroxy additives improved bound water and network stability. • The hydrogel exhibited a high thermo-optic coefficient of −5.727 × 10⁻⁴ °C⁻¹. • The fiber-optic SPR sensor exhibits a temperature sensitivity of 3.85 nm/°C. • The sensor enabled stable wearable monitoring of human respiration. Due to the excellent biocompatibility, flexibility and environmental responsiveness of hydrogels, the combination of responsive hydrogels with optical fiber sensors shows great potential for application in wearable devices. However, existing responsive hydrogels generally suffer from poor water-retention capacity, making them prone to dehydration-induced shrinkage or even cracking in air, which limits their ability to meet the requirements of wearable devices for long-term stable monitoring. This study designed a thermoresponsive hydrogel with high water-retention capacity. By reinforcing the hydrogel network crosslinking density with nanoclay and introducing highly hydrophilic materials to increase hydrogen-bond content, more bound water is formed, thereby enhancing the hydrogel’s water-retention capacity and thermal stability. Meanwhile, temperature variations induce reconstruction of water molecule configurations and the hydrogen-bond network, rendering the hydrogel’s refractive index highly sensitive to temperature changes. Experimental results show that the hydrogel exhibits excellent water retention over a temperature range of −10–100 °C and possesses a significant thermo-optic coefficient (−5.727 × 10⁻⁴ ℃⁻¹). When integrated with an optical fiber SPR sensor, it achieves high-sensitivity temperature detection (-3.85 nm/°C). Leveraging the hydrogel’s water-retention properties, the resulting optical fiber SPR temperature sensor is applied for long-term human respiratory monitoring. This study not only expands the application of hydrogels in the field of optical fiber sensing but also provides a new strategy for designing high-performance flexible optical fiber temperature sensors. Download: Download high-res image (238KB) Download: Download full-size image