Study of Microfluidic Chip with In Situ Prepared Chitosan Membrane Immobilized with Glucose Oxidase

2009 ◽  
Vol 60-61 ◽  
pp. 194-197
Author(s):  
Qiang Cao ◽  
Yi Xu ◽  
De Fu Song ◽  
Wei Wei Han ◽  
Xi Zhe Dong

A microfluidic chip with in-situ prepared chitosan membrane immobilized with Glucose Oxidase was developed as glucose oxidase reactor to detect human serum. The chitosan was prepared in-situ in the micro-channel as the immobilization material.Then,GOD was immobilized in the chitosan membrane, in which factors, such as the glutaraldehyde concentration, time of crosslinking and immobilization, buffer pH, were optimized with orthogonal experiments. The concentration of glutaraldehyde was finally chosen as 0.15%, time of crosslinking as 60 min, immobilization time as 15 h, and buffer PH as 8.0. The immobilization efficiency could reach up to 5U•cm2. The homemade microchip could be applied for rapid determination of glucose in serum, combining with the Luminol-K3Fe(SCN)3 Chemiluminescence reaction system. Under optimized conditions of sample velocity of 500uL•min-1, the concentration of K3Fe(SCN)3 of 1×10-2mol•L-1 and the concentration of luminol of 5×10-4 mol•L-1, the detection limit could achieved 1ug•mL-1.

2015 ◽  
Vol 69 (5) ◽  
Author(s):  
Qing-Qing Guan ◽  
Xiao-Dian Huang ◽  
Yan-Hua Zeng ◽  
Chao-Hai Wei ◽  
Ping Ning ◽  
...  

AbstractThis paper reports a headspace analysis technique for the determination of products, i.e., cyclohexanone (CE) and cyclohexanol (CL), of phenol hydrogenation in a supercritical water reaction system (SWRS) with water removal by hydrate formation. An addition of anhydrous calcium chloride leads to water absorption resulting in crystal water; thus, the samples can be quantitatively measured without the influence of water. After achieving equilibrium at 150­°C and maintaining it for 5 min, the obtained results showed a relative standard deviation of less than 5.3 % and the recovery ranged from 93 % to 104 %. The presented method is simple and accurate for the analysis of CL, CE and phenol in samples from phenol conversion in SWRS.


2015 ◽  
Vol 7 (7) ◽  
pp. 3006-3014 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
Esther Miguel ◽  
José L. Tadeo

A simple and rapid method is proposed for the determination of fourteen emerging contaminants in water and different herbal infusions (tea, chamomile, linden-blossom and pennyroyal).


2012 ◽  
Vol 468-471 ◽  
pp. 2842-2848 ◽  
Author(s):  
Yan Liu ◽  
Ping Ping Fan ◽  
Guang Li Hou ◽  
Ji Chang Sun ◽  
Yan Cheng ◽  
...  

Understanding marine biogeochemistry requires a network of global ocean in situ monitoring of various parameters on different scales in time and space. Among the various parameters involved in marine biogeochemistry, sediment chemistry is most important, and the organic matter fractions are the dominate factor in this parameter. However, classical methods of determining organic matter fractions consume a great deal of time and labor. In addition, some of these methods can produce high levels of pollution and are therefore not suitable for in situ studies. This study explored a method of rapid determination of organic matter fractions by ozonation chemiluminescence. In this method, the organic matter was separated into extractives, acid soluble fractions and acid insoluble fractions (AIF) using the classical method and then oxidized by ozone. The ozonation chemiluminescence characteristics of eight samples were subsequently used to set up a model to predict the concentrations of organic matter fractions. The model was tested using nine other organic samples and the results showed that it provided a better fit for the predicted acid soluble fractions. This study is the first to demonstrate the use of ozonation chemiluminescence for rapid determination of organic matter fractions; however, further study is required to enable its universal use.


2013 ◽  
Vol 726-731 ◽  
pp. 1283-1286
Author(s):  
Li Rui Liu ◽  
Li Qin Liu ◽  
Xue Qing Chen ◽  
Guo Qing Shi

A highly sensitive chemiluminescence enzyme immunoassay (CLEIA) method for the determination of bisphenol A (BPA) was developed, which used a secondary antibody labeled with horseradish peroxidase detected with a luminol-based substrate. Under the optimized conditions, the linear range was 0.01μg/mL~0.74μg/mL, and the detection limit was 0.008μg/mL. The average recovery for BPA in barreled water was 104%. This developed method could be applied for the selective, high-throughput, and rapid determination of BPA in barreled water.


2011 ◽  
Vol 110-116 ◽  
pp. 519-526 ◽  
Author(s):  
Ning Gan ◽  
Ling Hua Meng ◽  
Fu Tao Hu ◽  
Yu Ting Cao ◽  
Yuan Zhao Wu ◽  
...  

A novel disposable screen-printed immunosensor for rapid determination of highly sensitive C reactiveprotein (hs-CRP) in human serum has been developed in the experiment. The sensor was constructed on one screen-printed carbon electrode (SPCE) with HRP labeled anti-hs-CRP antibody functionalized Fe3O4@Au magnetic nanoparticles (HRP labeled anti hs-CRP/ Fe3O4@Au) as the biorecognition probes attracted on the surface of Fe (III) phthalocyanine (FePc)/ chitosan membrane modified screen-printed carbon electrode (SPCE|FePc/Chit/chitosan) by external magnetic field. FePc was acted as electron immediate. The modified electrode shows an excellent electrocatalytic activity for hs-CRP in phosphate buffer solution (pH=7.0). After the immunosensor is incubated with hs-CRP antigen solution at 37°C for 20 min, the access of activity center of the HRP to electrode is partly inhibited, which leads to a linear decrease of the catalytic efficiency of the HRP to the reduction of immobilized FePc by H2O2 at –50 mV in hs-CRP’s concentration ranges from 1.2 to 200 ng/mL. The detection limit was 0.5ng/mL. The immunosensor was successfully utilized for determination of hs-CRP in real serum samples of heart disease patients, whose results were consistent with that by ELISA method. The accuracy and precision of the assay were 91.5-104.4% and 15.8-24.4%, respectively. The immunosensor was reusable once constructed and can be regenerated by adding new nanoprobes on the surface of basal electrode through magnet on its bottom. It can greatly reduce the detection cost which is valuable for the early diagnosis of tumors.


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