Hyper-branched sensing polymer directly constructed on a resonant micro-cantilever for the detection of trace chemical vapor

Liu, Yongjing,Xu, Pengcheng,Yu, Haitao,Zuo, Guomin,Cheng, Zhenxing,Lee, D.-W.,Li, Xinxin The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.34

<P>A hyper-branched polymer is layer-by-layer self-assembled on a resonant micro-cantilever and, then, functionalized with sensing-terminals for the specific detection of the trace chemical vapor of dimethyl methylphosphonate (DMMP, a typical simulant for nerve agents). The hyper-branched polymer is directly constructed on the SiO<SUB>2</SUB> surface of the cantilever <I>via</I> an A<SUB>2</SUB> + B<SUB>4</SUB> layer-by-layer route, where A<SUB>2</SUB> and B<SUB>4</SUB> are complementary interacting groups which undergo coupled linking. After modification with 4-(2-(4-(allyloxy)phenyl)-1,1,1,3,3,3-hexafluoropropan-2-yl)phenol (APHFPP) groups specific to DMMP, the high specific-surface-area hyper-branched polymer provides very dense sensing sites to adsorb a great number of DMMP molecules for micro-gravimetric detection. Moreover, the sensing polymer possesses a “more branches but fewer roots” configuration on the cantilever surface to depress the cross-talk effect caused by adsorption induced cantilever spring-stiffening. Experimental results indicate that, self-assembled with the hyper-branched sensing polymer, the resonant cantilevers exhibit rapid and reproducible detection of trace DMMP (with the detection limit lower than 7.2 ppb) and effectively depressed parasitic frequency-shift from the cantilever spring stiffening effect. In addition, the sensor features satisfactory selectivity in the presence of water and organic solvents. When an alternative sensing-group of 2-allylhexafluoroisopropanol (AHFIP) is modified on the hyper-branched architecture, the cantilever becomes specifically sensitive to trace explosive vapor. Therefore, the developed technique for the functionalization of hyper-branched polymer directly grown on a cantilever provides a widely usable micro/nano sensing-platform for the detection of trace chemical vapors.</P> <P>Graphic Abstract</P><P>A hyperbranched polymer is directly grafted onto a resonant micro-cantilever surface. The polymer is functionalized with sensing terminal groups and it exhibits the selective, rapid and reproducible detection to trace dimethyl methylphosphonate, with the detection limit lower than 7.2 ppb. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm33202g'> </P>

Study on the Effect of Tween80 on the Properties of PVA/SCFs Composites

Liulan Lin,Weixuan Xu,Guomin Liu 한국고분자학회 2023 폴리머 Vol.47 No.5

Constructing polyurethane foams of strong mechanical property and thermostability by two novel environment friendly bio-based polyols

Zhenwu Kong,Shuping Huo,Guomin Wu,Jian Chen,Guifeng Liu 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.3

Two novel cardanol-based polyols were synthesized and used to construct polyurethane (PU) foams. The cardanol-based polyols with high reactivity were obtained from the epoxidation of cardanol, followed by the ring opening reaction of epoxy group with diethanolamine (DEA). Subsequently, PU foams were synthesized by these cardanolbased polyols. Compared with petroleum-based (PEG) PU foams, these green cardanol-based PU foams exhibit better mechanical property and higher thermostability. Scanning electron microscopy (SEM) tests show that the cells of cardanol- based PU foams are monodisperse, with fairly uniform spherical shape and regular size.

Chlorogenic Acid-Enriched Extract of Ilex kudingcha C.J. Tseng Inhibits Angiogenesis in Zebrafish

Tao Zhong,Linghua Piao,김현정,Xian De Liu,Shengnan Jiang,Guomin Liu 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.12

Kudingcha is a particularly bitter tasting tea that has been widely used in China to eliminate fever and itching eyes, and to clear blood toxins. Kudingcha is considered of value for its potential anticancer effects that are attributed to the presence of characteristic bioactive ingredients. The chlorogenic acid (CGA) derivatives 3-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, 3,5-0-dicaffeoylquinic acid, and 4,5-0-dicaffeoylquinic acid were separated from Ilex kudingcha C.J. Tseng extract by high-performance liquid chromatography (HPLC)–photodiode array detector (PDA) and HPLC-nuclear magnetic resonance (NMR). In Tg(flk1:EGFP) zebrafish embryos at 52 hours postfertilization (hpf), angiogenesis was significantly inhibited by kudingcha extract (KDCE) at concentrations of 400 and 500 μg/mL and CGA also showed significant inhibition in embryos treated with 80, 100, and 130 μg/mL. Endothelial cell apoptosis showed a dose-dependent increase in response to KDCE and CGA. CGA derivatives from KDCE could have potential as anticancer agents against tumor angiogenesis.

Nitrogen-Doped Hollow Carbon Nanospheres Derived from Dopamine as High-Performance Anode Materials for Sodium-Ion Batteries

Yurong Yang,Min Qiu,Li Liu,Dan Su,Yanmei Pi,Guomin Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.11

Designed as an anode material for sodium ion batteries, porous nitrogen-doped hollow carbon nanospheres (N-HCS, D = 200 nm) are successfully synthesized via the mature template-assisted method using silica and dopamine as template and carbon precursor, respectively. For detailed characterization of Raman, FTIR and XPS results, it is revealed that N-doping can form a disordered carbon structure and induce a large number of topological defects on carbon outer wall. The N-HCS electrode exhibits excellent cycling stability and rate capability, delivering a satisfying capacity of 306 mAh g-1 over 600 cycles at a discharging rate of 0.05 A g-1 and an attainable capacity of 188 mAh g-1 even at a high discharging rate of 3.0 A g-1. The excellent electrochemical performance of N-HCS can be attributed to the high content of pores. Moreover, the high content of pyridinic and graphitic N could facilitate the transfer of sodium ion and electron.

Supercritical CO2 extraction and response surface optimization of ginkgolic acids from ginkgo biloba exopleura

Lufei Tian,Minghao Zhou,Xiaomei Pan,Guomin Xiao,Yunqing Liu 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.8

Supercritical (Sc)-CO2 extraction was adopted to extract ginkgolic (G.) acids from ginkgo biloba exopleura. Response surface optimization was employed to maximize extraction recovery of G. acids from ginkgo biloba exopleura. The effects of pressure, temperature, CO2 mass flow rate, dosage of entrainer and extraction static-dynamic time on the yield of G. acids were investigated in detail, and the central composite design was used to maximize the extraction recovery of G. acids. The amounts of G. acids were analyzed by HPLC with the mixture of methanol and acetic acid solution as the mobile phase. The optimal process parameters for sc-CO2 extraction were determined to be: 31.3MPa extraction pressure, 46.1 oC extraction temperature and 11.1 g min−1 CO2 flow rate, 30mL ethanol entrainer, 1 h extraction static time and 2 h dynamic time. Under the conditions of optical extraction process, the average G. acids extraction rate was 74mg g−1.

MiR-137 inhibits the proliferation, invasion and migration of glioma via targeting to regulate EZH2

Gu Jingshun,Wang Juntong,You Aiwu,Li Jun,Zhang Yuyan,Rao Guomin,Ge Xuehua,Zhang Kun,Liu Xuan,Wang Dongchun 한국유전학회 2021 Genes & Genomics Vol.43 No.10

Background Gliomas are common malignant tumors in the nervous system, known for poor prognosis and low survival rate. Objective This study aims to explore functions of miR-137 in glioma progression and identify messenger RNAs (mRNA) regulated by miR-137, which provides new ideas for further exploration of glioma therapeutic targets. Methods Gene expression data were downloaded from the Cancer Genome Atlas database, and abnormally expressed miRNAs and mRNAs in glioma were analyzed. The expression of genes in 20 pairs of clinical tissue samples and glioma cell lines were detected through qRT-PCR, and the expression of proteins was detected through Western blot. Changes in cell proliferative level after transfection were detected via CCK8 assay, and changes in cell migratory and invasive abilities were detected by Transwell assay. Besides, dual-luciferase reporter assay was employed to testify binding relationship between two genes. Results Our study found that miR-137 was signifcantly and lowly expressed in glioma tissue and cell lines, and the prognoses of glioma patients with highly expressed miR-137 were more optimistic. Overexpressed miR-137 could remarkably inhibit proliferative, invasive and migratory abilities of glioma cells U87, while transfection of miR-137 inhibitor presented an opposite efect. Additionally, EZH2 was a direct target of miR-137 and overexpressed EZH2 efectively reversed the efect of miR-137 on glioma proliferation and migration. Conclusions Our study found that miR-137 could suppress the proliferation, invasion and migration of glioma cells through regulating the expression of EZH2. So far, we have found a novel regulatory pair that infuences glioma progression, providing a basis for further development of new therapeutic strategies.