Browsing by Author "Lin, Peng-Wei"

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Accurate real-time sensing tip for aqueous NO with optical fibers embedded in active hydrogel waveguide
(2018-02-01)
Chung, Chieh-Wen
;
Tsai, May-Jywan
;
Lin, Peng-Wei
;
Huang, Ding-Wen
;
Wang, Kuan-Hsun
A NO sensing tip is made by inserting two parallel optical fibers inside a poly 2-hydroxyethyl methacrylate (PolyHEMA) hydrogel waveguide mixed with the probe molecule 1, 2-Diaminoanthraquinone (DAQ). There is a length difference of 1 mm between the two fibers, and the light has to propagate through the difference from the short fiber to the long fiber. The total cross section area of the active hydrogel waveguide embedded with the fibers is only 3mm x 1.2 mm. For practical use the tip is housed in a needle for mechanical protection and the sensing tip is able to detect aqueous NO concentration around 1 mu M with time resolution about 5 minutes. Such a sensing tip can be used to monitor the medical conditions inside the brain after a stroke or a brain injury. (C) 2018 Author(s).
Hydrogel-based zinc ion sensor on optical fiber with high resolution and application to neural cells
(2020-08-15)
Tsai, May-Jywan
;
Cheng, Henrich
;
Ho, Hsin-Hsien
;
Lin, Peng-Wei
;
Liou, Dann-Ying
Solid-state zinc ion sensor is developed with high enough resolution and reproducibility for the potential application in brain injury monitoring. An optical diffuser is incorporated into the zinc ion sensor based on optical fiber and hydrogel doped with the fluorescent zinc ion probe molecule meso-2,6-Dichlomphenyltripyrrinone (TPN-Cl-2). The diffuser transforms the high-peak-intensity excitation light near the fiber end into a broad light with moderate local intensity to reduce the degradation of the probe molecule. Reversible detection can be reached for 1, 2, and 5 mu m (10(-6) Molar), with slopes 0.3, 0.6, and 0.8 respectively. This is the pathophysiological concentration range after brain injury. The sensor is applied to neuron-glial cultures and macrophage under the stimulation of lipopolysaccharide (LPS), KCl and oxygen/glucose deprivation (OGD) that reflect inflammation, depolarization and ischemia respectively, mimicking events after brain injury. The zinc ion level is raised to 4-5 mu m after LPS treatment, and then reduced to <3 mu m after the co-treatment with the herbal drug silymarin. The results suggest the conditions of the neural cells under stress can be monitored.