| 1. |
- Chang, Keke, et al.
(författare)
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Considerations on Circuit Design and Data Acquisition of a Portable Surface Plasmon Resonance Biosensing System
- 2015
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 15:8, s. 20511-20523
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to develop a circuit for an inexpensive portable biosensing system based on surface plasmon resonance spectroscopy. This portable biosensing system designed for field use is characterized by a special structure which consists of a microfluidic cell incorporating a right angle prism functionalized with a biomolecular identification membrane, a laser line generator and a data acquisition circuit board. The data structure, data memory capacity and a line charge-coupled device (CCD) array with a driving circuit for collecting the photoelectric signals are intensively focused on and the high performance analog-to-digital (A/D) converter is comprehensively evaluated. The interface circuit and the photoelectric signal amplifier circuit are first studied to obtain the weak signals from the line CCD array in this experiment. Quantitative measurements for validating the sensitivity of the biosensing system were implemented using ethanol solutions of various concentrations indicated by volume fractions of 5%, 8%, 15%, 20%, 25%, and 30%, respectively, without a biomembrane immobilized on the surface of the SPR sensor. The experiments demonstrated that it is possible to detect a change in the refractive index of an ethanol solution with a sensitivity of 4.99838 × 10(5) ΔRU/RI in terms of the changes in delta response unit with refractive index using this SPR biosensing system, whereby the theoretical limit of detection of 3.3537 × 10(-5) refractive index unit (RIU) and a high linearity at the correlation coefficient of 0.98065. The results obtained from a series of tests confirmed the practicality of this cost-effective portable SPR biosensing system.
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| 2. |
- Hu, Jiandong, et al.
(författare)
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Development of a Surface Plasmon Resonance Biosensing Approach for the Rapid Detection of Porcine Circovirus Type2 in Sample Solutions
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:10, s. e111292-
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Tidskriftsartikel (refereegranskat)abstract
- A sensitive and label-free analytical approach for the detection of porcine circovirus type 2 (PCV2) instead of PCV2 antibody in serum sample was systematically investigated in this research based on surface plasmon resonance (SPR) with an establishment of special molecular identification membrane. The experimental device for constructing the biosensing analyzer is composed of an integrated biosensor, a home-made microfluidic module, and an electrical control circuit incorporated with a photoelectric converter. In order to detect the PCV2 using the surface plasmon resonance immunoassay, the mercaptopropionic acid has been used to bind the Au film in advance through the known form of the strong S-Au covalent bonds formed by the chemical radical of the mercaptopropionic acid and the Au film. PCV2 antibodies were bonded with the mercaptopropionic acid by covalent -CO-NH- amide bonding. For the purpose of evaluating the performance of this approach, the known concentrations of PCV2 Cap protein of 10 mu g/mL, 7.5 mu g/mL, 5 mu g/mL, 2.5 mu g/mL, 1 mu g/mL, and 0.5 mu g/mL were prepared by diluting with PBS successively and then the delta response units (Delta RUs) were measured individually. Using the data collected from the linear CCD array, the Delta RUs gave a linear response over a wide concentration range of standard known concentrations of PCV2 Cap protein with the R-Squared value of 0.99625. The theoretical limit of detection was calculated to be 0.04 mu g/mL for the surface plasmon resonance biosensing approach. Correspondingly, the recovery rate ranged from 81.0% to 89.3% was obtained. In contrast to the PCV2 detection kits, this surface plasmon resonance biosensing system was validated through linearity, precision and recovery, which demonstrated that the surface plasmon resonance immunoassay is reliable and robust. It was concluded that the detection method which is associated with biomembrane properties is expected to contribute much to determine the PCV2 in sample solutions instead of PCV2 antibody in serum samples quantitatively.
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Duan, Zheng, et al.
(författare)
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Optical characterization of Chinese hybrid rice using laser-induced fluorescence techniques—laboratory and remote-sensing measurements
- 2018
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Ingår i: Applied Optics. - 1559-128X. ; 57:13, s. 3481-3487
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Tidskriftsartikel (refereegranskat)abstract
- Chinese hybrid rice of different varieties, growing in paddies in the Pingqiao district, north of Xinyang city, Henan province, China, was studied in detailed spectroscopic characteristics using laser-induced fluorescence. The base for the studies was the new South China Normal University mobile lidar laboratory, which was dispatched on site, providing facilities both for laboratory studies using a 405 nm excitation source as well as remote sensing measurements at ranges from around 40 m–120 m, mostly employing the 532 nm output from a Nd:YAG laser. We, in particular, studied the spectral influence of the species varieties as well as the level of nitrogen fertilization supplied. Specially developed contrast functions as well as multivariate techniques with principal components and Fisher’s discriminate analyses were applied, and useful characterization of the rice could be achieved. The chlorophyll content mapping of the 30 zones was obtained with the remote sensing measurements.
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| 5. |
- Mei, Liang, et al.
(författare)
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First attempt to monitor atmospheric glyoxal using differential absorption lidar
- 2012
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Ingår i: Proceedings of the SPIE. - : SPIE. ; 853412
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Konferensbidrag (refereegranskat)abstract
- Glyoxal (CHOCHO), as an indicator of photochemical “hot spots”, was for the first time the subject of a differential absorption lidar (DIAL) campaign. The strongest absorption line of glyoxal in the blue wavelength region – 455.1 nm – was chosen as the experimental absorption wavelength. In order to handle the effects of absorption cross-section variation of the interfering gas – nitrogen dioxide (NO2) – three-wavelength DIAL measurements simultaneously detecting glyoxal and NO2, were performed. The differential absorption curves, recorded in July 2012, indicate an extremely low glyoxal concentration in Lund, Sweden, although it is expected to be peaking at this time of the year.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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| 6. |
- Zhao, Guangyu, et al.
(författare)
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Reflectance and fluorescence characterization of maize species using field laboratory measurements and lidar remote sensing
- 2016
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Ingår i: Applied Optics. - 1559-128X. ; 55:19, s. 5273-5279
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence is an important technique to study photosynthesis and plants. Information on chlorophyll and other pigments can be obtained. We have been using a mobile laboratory in a Chinese experimental farm setting to study maize (Zea mays L.) leaves by reflectance and fluorescence measurements and correlated the spectroscopic signals to the amount of fertilizer supplied. Further, we studied five different species of maize using the remote monitoring of the fluorescence signatures obtained with the same mobile laboratory, but now in a laser radar remote-sensing configuration. The system separation from the target area was 50 m, and 355 nm pulsed excitation using the frequency-tripled output from an Nd:YAG laser was employed. Principal component analysis and linear discriminant analysis were combined to identify the different maize species using their fluorescence spectra. Likewise, the spectral signatures in reflectance and fluorescence frequently allowed us to separate different fertilizer levels applied to plants of the same species.
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| 7. |
- Zhao, Yawei, et al.
(författare)
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Fine-tuning the coordination atoms of copper redox mediators : an effective strategy for boosting the photovoltage of dye-sensitized solar cells
- 2019
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 7:20, s. 12808-12814
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Tidskriftsartikel (refereegranskat)abstract
- Natural systems have marvelously utilized copper complexes featuring sulfur-coordinating ligands, known as blue copper proteins, as efficient electron-transfer mediators in biological processes. Copper complexes with sulfur-coordinating ligands have been attempted as redox mediators in dye-sensitized solar cells (DSCs), the performance of which is not yet satisfactory and still remains less well explored. Herein, we report the application of new copper complexes bearing a tetradentate polythioether ligand, [(S-4)Cu](2+/+) (1(2+/+), S-4 = 1,4,8,11-tetrathiocyclotetradecane), as a redox mediator in DSCs in comparison with its N-4-tetradentate counterpart [(N-4)Cu](2+/+) (2(2+/+), N-4 = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane). Impressively, the changes of coordination atoms from N to S positively shift the formal redox potential of the copper complexes by 600 mV, leading to a remarkably high photovoltage approaching 1.0 V. This is one of the highest photovoltage values reported thus far for DSCs based on copper redox mediators.
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