Browsing by Author "Chao, Cheng-Han"

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A rapid and portable sensor based on protein-modified gold nanoparticle probes and lateral flow assay for naked eye detection of mercury ion
(2012-09-01)
Chao, Cheng-Han
;
Wu, Chung-Shu
;
Huang, Chung-Chih
;
Liang, Jie-Chian
;
Wang, Hsiao-Ting
Contamination of the environment with heavy metal ions has been an important worldwide concern for decades. Among them, mercury ion (Hg2+) is one of the heavy metal ion maintained in the detection because of its toxicity. In this study, we have designed the gold nanoparticle (AuNP) probes of carboxylic modified protein and employed the lateral flow assay to detect the Hg2+ without complicated instrumentations and technical expertise. The captured AuNP probes on the test zone and control zone of the sensor produced the characteristic red bands, enabling visual discrimination of Hg2+ concentrations. The demand of Hg2+ analysis in environmental applications requires parallel analytical strategies; such a method with simplicity and rapidity has enormous potential for the application of Hg2+ monitoring in environment, water, and food samples. (C) 2012 Elsevier B.V. All rights reserved.
Correlation between breath ammonia and blood urea nitrogen levels in chronic kidney disease and dialysis patients
(2020-07-01)
Chen, Chang-Chiang
;
Hsieh, Ju-Chun
;
Chao, Cheng-Han
;
Yang, Wei-Shun
;
Cheng, Hui-Teng
Previous studies have shown that breath ammonia (breath-NH3) concentration is associated with blood urea nitrogen (BUN) levels. However, interindividual variations in breath-NH3 concentrations were observed. Thus, the present study aimed to assess the effect of oral cavity conditions on breath-NH3 concentration and to validate whether the measurement of breath-NH3 concentration is feasible in clinical settings. A total of 125 individuals, including patients with stage 3 to 5 chronic kidney disease (CKD3-5), those on dialysis, and healthy participants, were recruited. A nanostructured sensor was used to detect breath-NH3 concentrations. Pre- and post-gargling as well as pre- and post-hemodialysis (HD) breath-NH3, salivary pH, and salivary urea levels were measured. Breath-NH3, salivary urea, salivary pH, and BUN levels were positively correlated to each other. Breath-NH3 concentrations were associated with BUN levels (r = 0.43, p < 0.001) and were significantly higher in CKD3-5 (p < 0.005) and dialysis patients (p < 0.001) than in healthy participants. Higher correlation coefficients were noted between breath-NH3 concentrations and BUN levels during follow-up (r = 0.59-0.94, p < 0.05). When the cutoff value of breath-NH3 was set at 523.65 ppb, its sensitivity and specificity in predicting CKD (BUN level >24 mg dl(-1)) were 87.6% and 80.9%, respectively. Breath-NH3 concentrations decreased after HD (p < 0.001) and immediately after gargling (p < 0.01). Breath-NH3 concentration, which was affected by gargling, was correlated to BUN level. The measurement of breath-NH3 concentration using the nanostructured device may be used as a tool for CKD detection and personalized point-of-care for CKD and dialysis patients. The current study had a small sample size. Thus, further studies with a larger cohort must be conducted to validate the effect of oral factors on breath-NH3 concentration and to validate the benefit of breath-NH3 measurement.
Morphology of Colloid-Derived Nanostructures and Structure-Induced Cytotoxicity under Electric Potential Stress
(2013-07-01)
Chao, Cheng-Han
;
Chang, Yu-Cheng
;
Hsu, Yi-Chieh
;
Liu, Fu-Ken
;
Chang, Feng-Chih
In this study, the morphology of two sizes of nanoparticles under different preparation solvents is evaluated. The vendor marked 5 nm sphere-like nanomaterials are not dispersed in water and toluene solvents, while the vendor marked 1-2 mu m nanoparticles are well-dispersed in the water and environments. The behavior of solvent-induced dispersion or aggregation of TiO2 nanomaterials has less relationship with the solvent polarity, but the dimension of nanomaterials has significant effect on the aggregation or dispersion behaviors. The morphology of nanoparticles from these solvents is, therefore, used to explain the observed cytotoxicity. The cytotoxicity of TiO2 particles with different sizes and concentrations are evaluated by MTT assay using murine embryotic fibroblast (NIH/3T3 cells). Most of the TiO2 materials of interest are not cytotoxicity, except for the minor toxic effect to 5 nm spherical nanomaterials at the concentration ranging from 5x10(-6) to 5x10(-2) mu g/mL. These spherical nanoparticles with 1-2 mu m dimension demonstrate no cytotoxicity for dosages ranging from 5x10(-6) to 50 mu g/mL, irrespective of the dosing time and dispersion behavior. The cytotoxicity of applied electrical potential is strongly dependent on the initial size of nanoparticles. The smallest 5 nm nanomaterials seems more to toxicity with duration of electric potential from 10 V stress. On the contrary, the vendor marked 1-2 mu m nanoparticles owing to largest sizes demonstrates no significant cytotoxicity.
Surface Effect of Assembling Enzyme and Modulation of Surface Enzyme Activity with Electric Potential Stress
(2012-06-01)
Chao, Cheng-Han
;
Li, Kun-Lin
;
Wu, Chung-Shu
;
Lee, Cheng-Che
;
Chiang, Han-Ping
The fluorescent marker of rhodamine B amine is successfully used to evaluate the immobilization capability onto silicon-based patterns fabricated by semiconductor manufacturing. Only the silicon dioxide surface, by means of fluorescent observation, can immobilize the rhodamine molecule by the sequential linkage of (3-aminopropyl) triethoxysilane (APTES) and glutaraldehyde. The phenol sulfotransferase enzyme is also successfully immobilized onto the silicon dioxide surface by the linking molecules of APTES and sulfosuccinimidyl 4-(N-maleimidomethyl)-cyclohezane-1-carboxylate in the home-made apparatus. The enzyme activity of the sulfotransferase is determined from the absorbance of 4-nitrophenol at 400 nm wavelength. The surface immobilized enzyme remains its activity for catalytic reaction at least 120-min duration. The surface saturation effect on the activity of immobilized enzyme is explained and ascribed to the surface diffusion effect of electric double layers. We can success control the surface immobilized enzyme by electric potential stress. The activity of enzyme is reduced under negative potential, while is enhanced under positive potential. The electric potential can induce the enzyme structure variation and modulate the enzyme activity due to the electrostatic effect.