An amperometric glucose biosensor
倍他米松磷酸钠 Betnesol-贝尔卡 低价高纯甾体激素原料药
外观 白色结晶粉末
分子式 C22H2量 516.4
规格一 10g
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价格 不开票 25/g
规格二 100g
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价格 不开票 16/g
规格三 500g
铝箔袋
价格 开票 10.5/g;不开票 9.5/g
规格四 1kg
铝听
价格 开票 9200/kg;不开票 8800/kg
缓解红、肿、痛等症状,且能抑制炎症晚期成纤维细胞的增生和肉芽组织的形成,减轻炎症引 起的瘢痕和粘连;糖皮质激素能提高机体对毒血症的耐受性,减轻细胞损伤,缓解毒血症状。 还能抑制中性粒细胞释放致热原和抑制下丘脑体温中枢,使热下降或防止发热。
主要用途 炎症、过敏性与自身免疫性疾病以及感染的综合治疗
产品应用 注射剂、滴剂等
公司主要生产基地位于通山,占地面积 3000 亩,主要生产雄性激素、雌性激素、孕激素、糖皮质激
素等甾体激素原料药。公司联合了武汉大学、华中科技大学、武汉工程大学等相关专家教授了组建了一批 技术专家团队,专门负责甾体合成工艺的优化和绿色生产工艺的开发,确保贝尔卡的生产技术处于国际领 先水平。贝尔卡生产的多个甾体产品已通过国家 GMP 认证、COS 认证,遍及亚洲、欧洲、北美、南美等
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武汉贝尔卡生物医药有限公司创建于 2001 年,原名通山县医药原料厂,是国家级高新技术企业。2014 年,公司董事会从战略发展角度出发,决定响应打造国家级产业基地的号召,将公司总部迁入武汉市生物
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医药园。与此同时,公司借力园区政策优势,进行产研合作,引入外商投资,正式更名为"武汉贝尔卡生物 医药有限公司"。
贝尔卡生物医药
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生物传感器的主要原理及应用英文
▪ 1916
First report on immobilization of proteins : adsorption
of invertase on activated charcoal
▪ 1922
First glass pH electrode
▪ 1956
Clark published his definitive paper on the oxygen electrode.
▪ 1962
First description of a biosensor: an amperometric enzyme electrodre for glucose (Clark)
▪ 1969
Guilbault and Montalvo – First potentiometric biosensor:urease immobilized on an ammonia
9
History of Biosensors
▪ 1987
▪ 1990 ▪ 1992 ▪ 1996 ▪ 1998
▪ 1998
▪ Current
Blood-glucose biosensor launched by MediSense ExacTech
SPR based biosensor by Pharmacia BIACore
Hand held blood biosensor by i-STAT
Launching of Glucocard
Blood glucose biosensor launch by LifeScan FastTake
Roche Diagnostics by Merger of Roche and Boehringer mannheim
热稳定的葡糖淀粉酶 英文
热稳定的葡糖淀粉酶英文英文回答:Thermostable glucoamylase is an enzyme that hydrolyzes the α-1,4-glucosidic bonds in starch, dextrin, and related oligosaccharides to produce glucose. It is typically produced by microorganisms, such as the fungus Aspergillus niger and the bacterium Bacillus stearothermophilus.Thermostable glucoamylase is an important industrial enzyme with a wide range of applications in the food, beverage, and pharmaceutical industries. It is used in the production of glucose syrups, high-fructose corn syrup, and other sweeteners. It is also used in the brewing industry to hydrolyze the starch in wort to produce fermentable sugars. In the pharmaceutical industry, thermostable glucoamylase is used in the production of antibiotics, such as penicillin and streptomycin.The thermostability of glucoamylase is an importantproperty for industrial applications because it allows the enzyme to be used at high temperatures, which can increase the efficiency of the enzymatic reaction. Thermostable glucoamylase is typically produced by microorganisms that are able to grow at high temperatures, such as thermophilic fungi and bacteria.中文回答:热稳定的葡糖淀粉酶是一种酶,它水解淀粉、糊精和相关低聚糖中的α-1,4-糖苷键以产生葡萄糖。
IST AG 生物传感器介绍说明书
Focus on BiosensorsBiosensors – a new Sensor Type from IST AGWhat are Biosensors?A biosensor is a device capable of detecting a certain substance or analyte with high specificity. Examples of such analytes are glucose, lactate, glutamine and glutamate. Most biosensors measure the concentration of an analyte in an aqueous solution, usually producing an electrical signal, which is proportional to the analyte’s concentration in its measuring range.An enzymatic biosensor comprises an enzyme, whichrecognizes and reacts with the target analyte generatinga chemical signal, a transducer, which produces a physicalsignal out of that chemical one, and an electronic amplifier,which conditions and amplifies the signal.Biosensors allow the analysis in complex biological media.The detection of a large number of compounds is ofgreat relevance not only for scientific research but alsofor process control in the chemical and food industry. It isalso indispensable in the health care field for the diagnosisand treatment of diseases and monitoring of illnesses.The pharmaceutical and biotechnology industries greatlydesire frequent to continuous analysis of biological media. Such analyses are conducted with the aid of analytical instruments like HPLC systems, which, although robust and reliable, are expensive and have a limited suitability for online operation. For this reason, the acquisition of Jobst Technologies GmbH positions IST AG as a key provider of high-performance and reliable online biosensors.Enzymatic Biosensors for Metabolic ParametersBack in the early 1960’s Clark and Lyons introduced the first glucose sensorusing an enzyme (glucose oxidase, GOx) as receptor, this enzyme beingspecific for glucose. Enzymes enable the highly specific measurement of theircorresponding analyte even in complex mixtures like fermentation broth andblood; it is like finding a needle in a haystack.Analytes such as glucose, lactate, glutamine and glutamate play an importantrole in the metabolism of living organisms. Glucose and glutamine support thecell function and growth; lactate is produced by cells and allows judging theefficiency of the cells metabolism; and glutamate is an amino acid consumedby cells. Each of these analytes requires a specific set of enzymes for itsdetection.The continuous (on-line) monitoring of the concentration of such parametersenables among numerous others■the generation, optimization and control of feeding strategies in cell cultures■the minimization of patients’ risks during surgery and intensive care■on-site analysis of food processes Presentations at the Biotechnica by Gerhard Jobst: ■Miniaturized analytical systems for bio/medical monitoring (Tuesday, 6th October / 3:30 - 4:00 pm / Hall 9 Booth C55) ■Biosensors for reliable monitoring (Wednesday, 7th October / 3:45 - 4:05pm / Hall 9 Booth F51)General structure of a biosensor. Sensors by IST AG use enzymes to detect glucose, lactate, glutamine and glutamate. The transducer principle is electrochemical, producing a current as output signal (amperometric).Focus on BiosensorsVersatile SensorsJobst Technologies GmbH has decades of experience in enzymatic biosensors. Enzymes are immobilized in a stack of four permeable polymeric membranes on top of platinum micro-electrodes, which pick up an electrical current originating from the enzymatic reaction. The superior membrane technology by Jobst Technologies allows for easy tuning of performance parameters like sensitivity, measurement range and response time. Moreover, this technology is compatible with sterilization by irradiation (gamma, beta). All this makes our biosensors suitable for a large variety of applications.Thanks to the small size of the electrodes, a single chip can hold several electrodes. The array sensor LV5 from Jobst Technologiesfeatures up to 6 sensitive electrodes where glucose, lactate, glutamine and glutamate can be detected simultaneously. Very small liquid samples can be analyzed as they flow through its 1-μL flow cell, thus being suitable for offline analysis as well as for online operation.Cross section of a flow-through LV5 biosensor featuring a flow-through cell for measuring of glucose, lactate, glutamine and glutamateLast but not least, each sensor is factory calibrated and marked in an automated process providing full traceability making it ideal for ready-to-use and single-use applications.Biomedical Application – A new Landmark Product: EIRUSOptimal treatment of critically ill patients requires the continuoussurveillance of their blood values. Recently, a world-leading providerof medical systems for hospitals, Maquet Critical Care, has beensetting a new standard by introducing the EIRUS platform specificallydeveloped to provide continuous monitoring of both glucose andlactate in critically ill patients. In addition to optimizing patient carequality, it reduces nurses workload compared to frequent intermittentblood analysis. This system relies on micro-dialysis technology thatfeeds a flow-through sensor developed and manufactured in Freiburg(Germany) by Jobst Technologies GmbH.During several days of continuous operation, EIRUS reports glucoseand lactate blood levels every minute and raises alerts wheneverthe values fall outside the preset ranges. This enables the rapidassessment of the patient’s glycemic condition, which in turn ensuresfor prompt and swift glucose management with insulin. Tighterglycemic control benefits not only diabetic patients but has beenshown to improve outcome also in non-diabetic critical care patients who frequently display a condition called ‘stress diabetes’.Elevated lactate levels (hyperlactatemia) are an indicator of increased morbidity and mortality. Monitoring of lactate enables an early and EIRUS system by Maquet for continuous monitoring of glucose and lactate in intensive care patients. Copyright: Maquet Critical Carecontinuous risk assessment, diagnosis and therapy minimizing patients’ risks.Focus on BiosensorsBiosensors – Their Application in BiotechnologyNowadays cell cultures aid in the development of new drug and medication. Animal cells are engineered to express proteins and antibodies used in the treatment of several illness and conditions. In order to maximize yield and product quality, conditions of cell cultures must meet optimal values. Monitoring of nutrients, like glucose, plays a vital role in the feeding strategy of a cell culture. One type of glucose sensors used in biotechnology requires a fluidic-dilution stage that has to be outside the culture vessel. Such systems show problems like large latency due to the transit time through the dilution stage; more footprint since an external analyzer is required; contamination risk because it is necessary to invasively take samples inside the bioreactor and dealing with the dead volume in the tubes. Other sensors cannot survive prolonged shelf storage after sterilization by irradiation. The technology developed by IST AG and Jobst Technologies allows for continuous glucose monitoring either inside the culturing vessel or by means of a probing parison of glucose values during batch cultureCalibration point (to Bioprofile) ~0.76mM/nA A Chinese-hamster-ovary (CHO) cell line wasused for a batch 1 culture in a conventionalglass bioreactor. The glucose concentration wascontinuously monitored for several days. Forthe control measurements a Nova BioprofileAnalyzer and a HPLC system were used. Dueto their robustness, sensors can be gammairradiated and stored before utilization. Sensorsare precalibrated; however a single calibrationat start provides increased accuracy throughoutthe entire cultivation lasting days. During thistime, a measurement point is acquired everysecond without requiring any manual work asthe used reference systems do.AcknowledgmentSpecial thanks to Dr. Caspar Demuth, Dr. Iris Poggendorf, Fabienne Seiler and Irène Stutz from the Zurich University of Applied Sciences (Institute for Biotechnology, Wädenswil, Switzerland) for carrying out the cultivation and providing us with the data.________________1 In a batch culture, the nutrient medium has starting glucose concentration and no further nutrient feeding is performed.Innovative Sensor Technology USA Division, 9516 W. Flamingo Rd., # 210, Las Vegas, NV 89147, Phone +1 702 894 9891, Fax +1 702 894 9993 ***************************,。
基于普鲁士蓝/L-半胱氨酸构建甲胎蛋白免疫传感器的研究
基于普鲁士蓝/L-半胱氨酸构建甲胎蛋白免疫传感器的研究朱宇萍;蒲星钥【摘要】通过静电吸附作用将普鲁士蓝(PB)固定在玻碳电极(GCE)表面,再依次电沉积L半胱氨酸(L—Cys)、氯金酸(HAuCl4).通过氯金酸与甲胎蛋白抗体(anti—AFP)中氨基的键合作用,将抗体固定在电极表面,最后用牛血清白蛋白(BSA)封闭电极表面的非特异性吸附位点,从而成功制备了一种新型的电流型甲胎蛋白免疫传感器.实验利用循环伏安法对电极的制备过程及性能进行了表征,结果表明该免疫传感器对AFP有很好的电流响应,其线性范围为0.01~200.0ng/mL,检出限为0.003ng/mL.该实验方法操作简便,制得传感器灵敏度高,实现了对AFP的定量分析.%First of all, a layer of Prussian blue is fixed on the surface of glassy carbon electrode (GCE). And then L- Cys, HAuCl4are electrolytically deposited in turn. Through the bonding effect of HAuCl4 and an anti-AFP, the antibody will be fixed on the electrode surface. Finally, bovine serum albumin (BSA) was applied to block the non-specific adsorption sites of the immunosensor, thus a new AFP Immunosensor comes successfully into shape. The preparation process of the electrode and its performance are then subjected to characterizationby cyclic voltammetry. The findings show: the said sensor exhibits a high response sensitivity to electric current with a linear range of 0.01-200.0ng/mL and the detection limit of 0. 003 ng/mL. The method is easy to operate and the sensor thus made is highly sensitive, which makes the quantitative analysis of AFP a reality.【期刊名称】《内江师范学院学报》【年(卷),期】2012(027)008【总页数】5页(P36-39,45)【关键词】普鲁士蓝;氯金酸;甲胎蛋白;免疫传感器【作者】朱宇萍;蒲星钥【作者单位】内江师范学院化学化工学院,四川内江641100;内江师范学院化学化工学院,四川内江641100【正文语种】中文【中图分类】O657.11甲胎蛋白(α-fetoprotein,AFP)是肝癌细胞表达的高特异性蛋白质,很多肝癌病人(70%~80%)在发病期间都有AFP基因高表达的特征.最近,研究者对肝癌细胞特异性标志物AFP进行长时间的研究,发现AFP具有抑制PTEN的生物学功能,导致肝癌细胞耐受全反式维甲酸诱导的凋亡,这是AFP新功能的发现[1].因此,对于人体AFP的检测有着十分重要的意义.将电化学方法与免疫反应结合起来的电化学免疫传感器对AFP的检测具有分析快速、灵敏和测量精确、预处理简单、便宜和仪器小型化的特色[2].但是对于传感器制备过程中抗体的固载已成为电化学生物传感器领域研究的重点.近年来,随着纳米技术的不断发展,种类繁多的纳米材料已广泛应用到电化学生物传感器的制备中.探寻一种新型纳米材料,并将其应用于免疫传感器的制备,将为临床医学检测提供一定的参考价值.普鲁士蓝(Prussian blue,PB),因其对于过氧化氢有良好的催化还原作用,被称为“人造过氧化氢酶”,它具有良好的化学稳定性、电催化特性,且制备简单、成本低廉[3-4],最重要的是PB具有良好的电化学活性,能加速电极与氧化原中心电子的传输[5],是制备电分析免疫传感器的理想材料.通过静电吸附作用,将PB固定在玻璃电极(glassy carbon electrod,GCE)表面.带正电的L-半胱氨酸(L-cysteine,L-Cys)含有丰富的巯基、氨基和羧基,利用LCys的巯基与金易形成硫金键的特征[6],将HAuCl4沉积在修饰电极表面,以达到吸附更多的anti-AFP.实验将这三种材料的优点结合起来为抗体的固定提供了一个良好的界面,对成功研制新型的AFP免疫传感器提供了保障.CHI660C电化学工作站(上海辰华仪器公司),BRANSON 200超声清洗仪(美国BRANSON公司),pH计(奥豪斯仪器(上海)有限公司),135-S电子天平(瑞士 Mettler-toledo公司),所有玻璃仪器用 K2Cr2O7-H2SO4浸泡,超声清洗仪Branson 200 超声,晾干.传 anti-AFP 及 AFP、BSA、HAuCl4、L-Cys、磷酸缓冲溶液(pH4,4.5,5,5.5,6,6.5,7)、无水乙醇等(以上试剂均为分析纯).实验室用水均为去离子水.按参照文献[7]的报道作了少量改进,用氯化铁和铁氰化钾反应制备纳米PB.33mg铁氰化钾与16.3mg氯化铁以适量0.1mol/L KCl+0.1mol/L HCl溶解,并加入适量的H2O2形成纳米.其反应机理为将GCE在1.0,0.05μm 的 Al2O3糊中将电极表面抛光成镜面,在急速水流下冲洗以除去抛光粉,用蒸馏水超声清洗3次,每次60s,最后再用无水乙醇超声2次,室温晾干.将处理好的电极放入新制的PB(用盐酸调节溶液的pH为1.0~1.5)溶液中于0.4V电沉积60s后,取出晾干.将制得的PB修饰电极于100℃恒温烘干1h,取出电极在室温下冷却.然后将电极依次置于含0.1mol/L KCl+0.1 mol/L HCl、0.02mol/L 的 L-半胱氨酸中循环扫描.之后将电极放入1%(w%)的HAuCl4溶液中电沉积并将电极浸泡在anti-AFP溶液中,于4°C下冷藏8h.最后将电极浸入0.25% (w%)的BSA溶液中约30min,封闭电极上的非特异性吸附位点[8],即制得免疫电极.将电极置于4°C的冰箱中保存待用,如图1所示.实验采用循环伏安法(Cyclic Voltammetry,CV)对电极的制备过程进行逐步表征.检测电极电流用三电极体系:饱和甘汞电极(SCE)参比电极,铂丝电极作对电极,被修饰的GCE为工作电极[9],将电极置于电位区间为-0.2~0.5V,扫描速率为50mv/s,PBS(pH6.0)溶液中表征.如不另加说明,实验均在25℃下进行.用CV表征了电极在组装过程中的电化学特性,其结果见图2.曲线a是裸GCE电极在PBS溶液中的循环伏安表征图.将PB沉积于玻碳电极表面后峰电流显著上升(曲线b),这是因为PB本身为电子媒介体,具有良好的电化学活性,能加速电极中电子的传递;将上述修饰电极置于L-Cys中沉积后,由于L-Cys组装膜在一定程度上阻碍电子的传递[10],从而使峰电流降低(曲线c);沉积 HAuCl4的电极峰电流显著升高(曲线d);曲线e是anti-AFP固定在电极表面之后的循环伏安图,蛋白质大分子阻碍电子传输,使峰电流降低[11];当BSA封闭非特异性吸附位点,峰电流继续降低(曲线f);最后将修饰好的免疫传感器放于AFP 抗原中孵育,当溶液中的抗原和电极表面的抗体充分反应后,生成的电化学惰性蛋白质层[11],进一步阻碍了电子传输,使其响应电流再次下降(曲线g).实验考察了免疫传感器在扫速分别为:10,30,50,80,100,120,140,160,180,200,300,350mv/s下的响应电流.由图3可见,免疫传感器呈现准可逆的氧化还原曲线.随着扫速由里到外的增加,氧化还原峰电流值也随之增加,并且和扫速成平方根成正比(图3插图),与柴荣[12]研究的结果一致.说明电极氧化还原受扩散过程控制.缓冲溶液pH对免疫传感器的影响主要有两个方面:一方面影响抗原、抗体的活性;另一方面对亲和性的影响[14].在PBS溶液的pH4.0~7.0范围内用循环伏安法测试电极的循环伏安曲线(如图4),当pH5.0时,氧化还原峰电流均达到最大值,这是因为纳米PB在酸性环境下具有更好稳定性[15],故选择pH 5.0的PBS作为基体溶液.温度能影响免疫蛋白分子的活性.温度过低,会降低蛋白质分子的活性,使抗原与抗体结合的速度慢,时间长;温度较高时,蛋白质分子活性高,抗原抗体结合的速度快,时间短[16].但是,过高的温度将导致抗原、抗体失活或蛋白质流失.因此,实验考察了在5~40℃范围内温度与反应信号的关系.结果见图5,随着温度的升高,还原峰响应电流逐步减小,说明抗原和抗体反应的程度逐渐增加.当温度为30℃时AFP抗体对抗原的结合已经比较稳定.当温度升高时,免疫反应速率增加,但温度过高也会引起蛋白质变性而失活,减少使用寿命,温度太低会使抗原抗体结合不够或时间加长,不利于电极的的稳定性.因此综合考虑选择实验温度为25℃.反应时间影响免疫反应的程度.将免疫传感器放入20ng/mL 抗原溶液中依次反应1,2,5,8,10,12,15,20min,并用CV测定其响应电流的变化,其结果如图6所示.实验发现,反应10min时,电极上结合的抗原量达到饱和,响应电流逐渐稳定.最佳培育时间与黎雪莲[17]研究的结果有一定的差异.故实验过程中选择的最佳培育时间为10min.在最优实验条件下,测定了免疫传感器对AFP的响应电流[17].由图7可知,AFP抗原的浓度越高,敏感膜上生成的抗原-抗体复合膜就越多,响应电流下降就越明显(从外到内浓度分别为0.01,0.05,0.1,0.5,1,10,20,40,80,100,150,200ng/mL).AFP的浓度在0.01~200ng/mL范围内,该免疫传感器与峰电流值呈良好的线性关系.其线性回归方程为相关系数为0.9911,检测限为0.003ng/mL,如图8所示.实验考查了免疫传感器的选择性能.将免疫传感器分别置于含有20ng/mL AFP抗原的标准溶液和含有20ng/mL AFP抗原以及模拟人体环境可能存在的干扰物质的溶液中,孵育10min后,进行CV 检测,记录其响应电流值[8-9,18];再将其置于含有20ng/mL AFP抗原以及模拟人体环境可能存在的干扰物质的溶液中重复上述步骤.加入的干扰物质有:癌胚抗原、乙肝表面抗原以及牛血清白蛋白、抗坏血酸.实验显示,2次测量的响应电流无显著变化,表明其干扰物质对测定不会产生影响,该免疫传感器有良好的选择性.利用纳米PB和L-Cys成功研制了一种新型的电流型AFP免疫传感器,通过循环伏安法考察了电极表面的电化学特性.纳米PB可作为电子媒介体,提高了灵敏度.该免疫传感器具有灵敏度高、线性范围宽、响应时间快、稳定性好、检测下限低,成本低等特点.该方法可应用于其他免疫物质的测定,有望应用于临床诊断.【相关文献】[1]Hu JS,Wu DW,Ling S,et al.GP73aresident Golgiglycoprotein is sensibility and specificity for hepatocellular carcinoma of diagnosis in a hepatitis B endemic Asia population[J].Med Oncol,2010,27(2):339-345.[2]王力平,庄惠福.EIA法与RIA法检测甲胎蛋白结果比较[J].标记免疫分析与临床,1999(6):51-52.[3]Ricci F,Palleschi G.Sensor and biosensor preparation,optimisation and applications of Prussian Blue modified electrodes.Biosens Bioelectron.2005,21(3):389-407.[4]Karyakin A A,Karyaking E E,Gorton L.Amperometric biosensor for glutamate using Prussian blue-based“artificial peroxidase”as a transducer for hydrogen peroxide [J].Analytical Chemistry,2000,72:1720-1723.[5]Fiorito P A Goncales V R,Ponzio E A,et al.Synthesis,characterization and immobilization of Prussian blue nanoparticles.A potential tool for biosensing devices [J].Chemical Communications,2005,21(3):366-368.[6]黎雪莲,袁若,柴雅琴,等.基于 Nafion/双层L-半胱氨酸-纳米金固定辣根过氧化氢酶的生物传感器[J].化学传感器,2005,25(3):21-25.[7]付平,袁若,柴雅琴,等.基于壳聚糖-纳米金/纳米普鲁士蓝/L-半胱氨酸修饰的葡萄糖传感器的研究[J].化学学报,2008,66(15):421-425.[8]王晋芬.基于纳米复合材料构建电流型免疫传感器和过氧化氢生物传感器的研究[D].北碚:西南大学,2008.[9]卓颖.基于纳米金/硫堇/Nafion自组装的新型电流型酶免疫传感器的研究[D].北碚:西南大学,2006.[10]Zhuo Y,Yuan R,Chai Y Q,et.al.Enhancement of carcinoembryonic antibody immobilization on gold electrode modified by gold nanoparticles and SiO2/Thionine nanocomposite[J].Journal of Electroanalytical Chemistry,2009,628(1/2):90-96. [11]Zhuo Y,Yuan R,Chai Y Q,et al.A tris(2,2′-bipyridyl)cobalt(Ⅲ)-bovine serum albumin composite membrane for biosensors,biomaterials,2006,27(31):5420-5429.[12]柴荣.基于纳米金微粒为载体的电化学免疫传感器的研究[D].北碚:西南大学,2008. [13]闵丽根,袁若,柴雅琴,等.基于纳米金与碳纳米管-纳米铂-壳聚糖纳米复合物固定癌胚抗原免疫传感器的研究[J].化学学报,2008,66(14):1676-1680.[14]Ricci F,Amine A,Palleschi G,et al.Prussian Blue based screen printed biosensors with improved characteristics of long-term lifetime and pH stability[J].Biosens.and Bioelectron.2003,18(2/3):165-174.[15]朱宇萍,袁若,柴雅琴,等,基于纳米金与牛血清蛋白-二氧化钛复合物固定甲胎蛋白免疫传感器的研究[J].内江师范学院学报,2011,26(4):45-49.[16]黎雪莲.新型生物分子固定技术用于构建生物传感器的研究[D].北碚:西南大学,2006. [17]殷冰.新型电流型生物传感器用于检测葡萄糖和癌胚抗原的研[D].北碚:西南大学,2008.。
重症肺部感染患者血清胆碱酯酶水平与患者预后的关系
重症肺部感染患者血清胆碱酯酶水平与患者预后的关系曹莉莉;孟晓皓;张春玲【摘要】目的探讨重症肺部感染患者血清胆碱酯酶(S-ChE)水平与患者病情预后之间的关系.方法回顾性分析2016年1~12月期间阜新市中心医院重症监护病房收治的84例重症肺部感染患者的临床资料,根据患者最终结局分为存活组(n=58)与死亡组(n=26),比较两组患者的性别、年龄、合并疾病、S-ChE、急性生理与慢性健康评分(APACHEⅡ评分)、多器官功能障碍综合征(MODS)评分、社区获得性肺炎严重程度评分(CURB-65评分)、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、氧合指数,将差异具有统计学意义的因素进行Logistic回归分析,探讨重症肺部感染患者S-ChE与病情预后的关系.结果存活组患者的S-ChE、氧合指数分别为(4.48±1.34)kU/L、(167.1±69.7)mmHg,明显高于死亡组的(2.75±1.29)kU/L、(114.2±70.0)mmHg,APACHEⅡ评分、MODS评分、CURB-65评分分别为(16.4±5.2)分、(4.4±2.3)分、(2.2±0.4)分,明显低于死亡组的(25.8±5.1)分、(8.2±2.5)分、(3.4±0.5)分,差异均具有统计学意义(P<0.05);Logistic回归分析结果显示,S-ChE、APACHEⅡ评分、MODS评分、CURB-65评分均为重症肺部感染患者病情预后的独立危险因素(P<0.05).结论重症肺部感染患者血清胆碱酯酶水平与患者的预后关系密切,且血清胆碱酯酶水平越低,患者预后越差.【期刊名称】《海南医学》【年(卷),期】2018(029)019【总页数】4页(P2674-2677)【关键词】重症肺部感染;血清胆碱酯酶;预后【作者】曹莉莉;孟晓皓;张春玲【作者单位】阜新市中心医院呼吸内科,辽宁阜新 123000;阜新市中心医院呼吸内科,辽宁阜新 123000;阜新市中心医院呼吸内科,辽宁阜新 123000【正文语种】中文【中图分类】R563肺炎是感染性疾病中导致死亡率最高的疾病,且在人类总死亡率中占据第5~6位,严重危害人类健康[1-2]。
电化学方法检测胆固醇的研究进展
第52卷第8期 辽 宁 化 工 Vol.52,No. 8 2023年8月 Liaoning Chemical Industry August,2023收稿日期: 2022-08-21电化学方法检测胆固醇的研究进展飏吕龙,顾婷婷,尚帅,林常瑞(辽宁科技大学 化学工程学院,辽宁 鞍山 114051)摘 要: 随着人类生活质量的提高,胆固醇的检测成为一个重要的研究课题。
电化学方法具有选择性强、检测速度快等优点。
综述了近年来利用电化学方法在有酶和无酶的条件下测定胆固醇含量的电化学原理和最新进展,并对用电化学方法检测胆固醇进行了展望。
关 键 词:胆固醇;有酶;无酶;电化学传感器中图分类号:O657.1 文献标识码: A 文章编号: 1004-0935(2023)08-1193-04胆固醇是一种化学式为C 27H 46O 的环戊烷多氢菲的衍生物。
胆固醇是人体内最普遍存在的化合物,主要存在于大脑的中枢神经组织,另外还存在于肾脏、脾脏、皮肤以及胆汁。
胆固醇能经由多种途径进入身体。
高胆固醇会引起慢性心脏病、高血压、脑血栓等致命的心脑血管病[1-2]。
目前,胆固醇的检测方法有高效液相色谱法[3-4],比色法[5-6]和光谱法[7-8]等,这些检测方法一般存在检测周期长、灵敏度低、选择性、仪器标准化、样品预处理要求高等缺点。
另一方面,电化学方法[9-10]由于具有选择性强、制备方法简单、仪器简单、成本低、操作方便、检测速度快等特点,受到研究者的广泛关注[11]。
电化学检测胆固醇的方法包括包括差分脉冲伏安法(DPV)[12]、安培法[13-14,15-17]、电荷转移(CT)[18]、循环伏安法(CV )[19-22]、线性扫描伏安法 (LSV)[23-24]、电化学发光法(ECL)[25]和电化学阻抗谱(EIS)[26]。
在这些方法中,电流测量法是许多研究中最常用和最敏感的方法[27]。
随着技术的发展,基于各种材料制备出的胆固醇电化学传感器成为研究热点之一。
ITO电极上催化伏安法测定锇联吡啶的研究
ITO电极上催化伏安法测定锇联吡啶的研究邹蕊【摘要】An electron transfer mediator osmium bipyridine was synthesized. The electrochemical behaviors of osmi- um bipyridine at ITO electrode were studied and the catalytic reaction kinetics of it in system ofglucose/glucose ox- idase was measured. The homogeneous reaction rate constant (Ks ) is 2.07 ×10^-2cm/s, and the first- order reac- tion rate constant (Kf) and second -order reaction rate constant (Kmed) in catalyzed reaction are 1.05 × 10^-3s-1 and 1.57× 10^4 L/( mol. s), re spectively. The detection limited is 0. 016 μmol/L. Therefore, as an electrochemical label, osmium bipyridine can be used to construct biosensor for the catalyzed signal amplification.%合成了电子转移介体锇联吡啶Os(bpy)3,采用催化伏安法研究了Os(bpy)3在ITO电极上的电化学行为,并对Os(bpy)3在葡萄糖一葡萄糖氧化酶体系中的催化反应动力学常数进行了测定。
Os(bpy)3的均相反应速率常数Ks为2.07×10^-2cm/s,催化反应中一级反应速率常Kf为1.05×10^-3s^-1,二级反应速率常数kmed为1.57×10^4L/(mol.s)。
二型糖尿病骨质疏松英语
二型糖尿病骨质疏松英语Type 2 Diabetes Mellitus and Osteoporosis: A Comprehensive Review.Introduction.Type 2 diabetes mellitus (T2DM), a chronic metabolic disorder characterized by hyperglycemia and insulin resistance, has become a global epidemic. Osteoporosis, a bone disease marked by low bone mass and structural deterioration of bone tissue, often leads to increased bone fragility and fracture risk. Recent studies havehighlighted a significant association between T2DM and osteoporosis, suggesting a bidirectional relationship between these two conditions. This review aims to explore the interplay between T2DM and osteoporosis, focusing on the pathogenesis, risk factors, clinical manifestations, diagnosis, and management of this complex comorbidity.Pathogenesis.The pathogenesis of osteoporosis in T2DM patients is multifaceted and involves several interrelated mechanisms. Hyperglycemia, a hallmark of T2DM, is known to affect bone health through various pathways. Chronically elevated blood glucose levels can stimulate osteoclastogenesis, leading to increased bone resorption and reduced bone mass. Additionally, hyperglycemia impairs osteoblast function, reducing bone formation and contributing to the development of osteoporosis.Furthermore, insulin resistance and the associated hyperinsulinemia in T2DM patients can also influence bone health. Insulin is a potent anabolic hormone that stimulates bone formation. However, in individuals with insulin resistance, the bone-forming effects of insulin are blunted, while its bone-resorbing effects are enhanced. This imbalance contributes to the development of osteoporosis in T2DM patients.Risk Factors.Several risk factors for osteoporosis in T2DM patients have been.。
2014-ACS Appl. Mater. Interfaces-酚变醌
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mesoporous carbon,16 graphene,2 and carbon nanofiber (CNF),17 have been widely employed as the immobilization materials of enzymes in biosensors, which can be attributed to their large specific surface area, excellent conductivity, and satisfactory biocompatibility. Among these materials, CNF possesses much larger functionalized surface area compared to that of CNT and is more suitable for immobilization and stability of enzyme. It has been proven that CNF is an outstanding matrix for the development of biosensors, which is far superior to the carbon nanotube.17 Notably, the CNF possesses a history of more than a century; the carbon filaments discovered in 1889 may be the earliest CNF.18 After more than a century of development, various methods used for CNF preparation have been developed, such as arc-discharge,19 laser ablation,20 chemical vapor deposition (CVD) methods,21 and others. Electrospinning, known as a facile and convenient process technique, produces nanofibers or microfibers with different diameters using a variety of polymers. Carbonization of electrospun polyacrylonitrile nanofibers can be employed to fabricate CNF.22 In addition, to our best knowledge, CNF from CVD usually contains some impurities, e.g., metal catalyst and graphite particle, which requires a further complicated
反相微乳法制备普鲁士蓝类立方形纳米粒子
反相微乳法制备普鲁⼠蓝类⽴⽅形纳⽶粒⼦反相微乳法制备普鲁⼠蓝类⽴⽅形纳⽶粒⼦及其电化学性能测试⼀、⽬的要求1、了解反相微乳法制备纳⽶粒⼦的原理,熟练掌握反相微乳法制备纳⽶粒⼦的步骤、可对条件优化来控制纳⽶粒⼦形状;2、了解纳⽶粒⼦的表征⽅法,⽤红外、TEM等进⾏表征;3、熟悉并了解⽣物传感器的制备⽅法和双氧⽔的测定⽅法;4、了解电化学⼯作站的使⽤⽅法⼆、实验原理“微乳液”是由⽔、油、表⾯活性剂和助表⾯活性剂组成的澄清透明、各向同性的热⼒学稳定体系。
根据结构的不同可以把微乳液分成3种类型: O/W (⽔包油)型微乳液、W/O (油包⽔)型微乳液和双连续型微乳液。
在微乳体系中,⽤来制备纳⽶粒⼦的⼀般都是W/O型微乳液。
W/O微乳液中的⽔核被表⾯活性剂和助表⾯活性剂所组成的单分⼦界⾯层所包围,分散在油相中,其⼤⼩约为⼏nm到数10个nm。
这些⽔核增溶⼀定浓度的反应物,并且由于其具有很⼤的界⾯⾯积⽽使物质交换以很⼤的通量进⾏,因此可以作为合成纳⽶粒⼦的“微型反应器”。
.W/O 型微乳液制备纳⽶材料的⽅法⼀般有以下两种:(1)配置2个分别增溶有反应物A、B的微乳液,⼀种含有⾦属粒⼦前驱体(多为⾦属盐),另外⼀种含有⽤来还原⾦属粒⼦前驱体的沉淀剂。
此时由于胶团颗粒间的碰撞、融合、分离、重组等过程,发⽣了⽔核内物质的相互交换或物质传递,引起核内的化学反应(包括沉淀反应、氧化-还原反应、⽔解反应等),且产物在⽔核内成核⽣长。
当⽔核内的粒⼦长到最后尺⼨,表⾯活性剂就会附在粒⼦的表⾯,使粒⼦稳定并防⽌其进⼀步长⼤。
由于⽔核半径是固定的,不同⽔核内的晶核或粒⼦之间的物质交换不能实现,所以⽔核内粒⼦尺⼨得到了控制。
(2)将⼀种反应物增溶在微乳液的⽔核内,另⼀种反应物以⽔溶液形式滴加到前者中,⽔相内反应物穿过微乳液的界⾯膜进⼊⽔核内与另⼀反应物作⽤产⽣晶核并⽣长,产物粒⼦的最终粒径是由⽔核尺⼨决定的。
普鲁⼠蓝类配合物是⼀种蓝⾊染料,具有优良的电化学性能,同时稳定性好,制备成本低等优点,因⽽可以应⽤于化学修饰电极、电显⾊、⼆次电池等⽅⾯。
生物传感器-文献综述-3110100122-邵建智
检测葡萄糖浓度的酶传感器研究文献1题目:Real-Time Noninvasive Measurement of Glucose Concentration Using a Microwave Biosensor检测机理:通过微波生物传感器,用探头尖端和葡萄糖溶液之间的实时电磁相互作用来检测葡萄糖浓度,微波生物传感器包括一个耦合到探针尖端的电解质谐振器,由于微波谐振器和葡萄糖溶液之间的电磁相互作用,葡萄糖浓度的变化与微波的反射系数直接相关,并且检测分辨率达1毫克/毫升。
检测仪器:如图所示的微波传感器。
分子识别元件:镀金探针尖端检测步骤:微波生物传感器包括一个耦合到探针尖端的电解质谐振器,其共振频率约为4.6GHz,为了获得高的灵敏度,有圆顶点的镀金探针尖端和圆筒形端部需要连接到谐振器的内部循环当中,硅管壁厚TT = 0.4毫米和内径TG = 2.5毫米被安装在圆筒形探针尖端的端部,如图所示。
整个系统放置在机械振动隔离台,测量全部在电磁内进行,其内环境,温度与湿度均自动控制,管内葡萄糖的流速保持着2毫米/秒的速度,利用网络分析仪,可以测得微波谐振器的反射系数,从而得出葡萄糖的浓度。
检测限:0.003dB/(mg/ml)检测时间:实时监控并检测创新性:可以进行无创实时检测不足:微波遥感平台应用不够广泛文献2题目:Measurement of Glucose Concentration in Blood Plasma Based on a Wireless Magnetoelastic Biosensor检测机理:血浆中的无线磁弹性葡萄糖生物传感器描述的基础上,使用质量敏感的磁传感器作为传感器。
葡萄糖生物传感器的制作是用pH敏感的聚合物和葡萄糖氧化酶(葡萄糖氧化酶)和过氧化氢酶的生物层涂布的带状,磁致弹性传感器。
将pH响应聚合物溶胀或收缩,从而改变传感器质量负荷,分别响应于增加或减少的pH值。
在血浆中的葡萄糖氧化酶催化的氧化反应产生葡糖酸,从而使pH敏感聚合物收缩,这反过来又降低了传感器的质量负荷。
纳米金-还原氧化石墨烯修饰葡萄糖氧化酶传感器的制备及其电流法检测饮料中的葡萄糖
纳米金-还原氧化石墨烯修饰葡萄糖氧化酶传感器的制备及其电流法检测饮料中的葡萄糖郑海松;毛慎;丁顺;陈雪娇;李云飞;宗凯;操小栋;叶永康【摘要】利用纳米金(AuNPs)与还原氧化石墨烯(rGO)复合纳米材料制备了葡萄糖氧化酶生物传感器并用于饮料中葡萄糖含量的检测.将壳聚糖作为还原剂及稳定剂,通过一步法合成了AuNPs-rGO复合材料,并通过物理吸附固定葡萄糖氧化酶(GOx)来制作GOx生物传感器.该传感器在磷酸盐缓冲溶液(0.1 mol/L,pH6.0)中,-0.45V(vs.Ag/AgCl)电位下电流法检测葡萄糖含量,线性检测范围为0.01~0.88mmol/L,灵敏度为22.54 μA·mmol-1·L·cm-2,检出限为1.01 μmol/L,且表观米氏常数为0.497 mmol/L.该传感器用于多种饮料中葡萄糖含量的直接检测,结果满意.%An amperometric glucose oxidase (GOx) biosensor based on gold nanoparticles (AuNPs) -reduced graphene oxide (rGO) was fabricated for the detection of glucose in beverages.AuNPs-rGO composite was synthesized by one-pot method with chitosan as reducing and stabilizing agent.It was used as the matrix for GOx immobilization via physical adsorption technique to fabricate the GOx-based biosensor.The biosensor was applied in the amperometric determination of glucose at-0.45V(vs.Ag/AgCl) in a phosphate buffer (0.1 mol/L,pH 6.0).There was a linear response to glucose in the concentration range of 0.01-0.88 mmol/L,with a sensi tivity of 22.54 μA · mmo1-1.L · cm-2 and a detection limit of 1.01μmol/L.The apparent Michaelis-Menten constant was rather small(0.497 mmol/L).The constructed biosensor was successfully applied in the detection of glucose in beverages.【期刊名称】《分析测试学报》【年(卷),期】2017(036)009【总页数】5页(P1114-1118)【关键词】纳米金;还原氧化石墨烯;葡萄糖氧化酶;电流法;饮料;葡萄糖【作者】郑海松;毛慎;丁顺;陈雪娇;李云飞;宗凯;操小栋;叶永康【作者单位】安徽出入境检验检疫局技术中心,安徽合肥230022;合肥工业大学食品科学与工程学院,安徽合肥230009;合肥工业大学食品科学与工程学院,安徽合肥230009;安徽出入境检验检疫局技术中心,安徽合肥230022;安徽出入境检验检疫局技术中心,安徽合肥230022;安徽出入境检验检疫局技术中心,安徽合肥230022;合肥工业大学食品科学与工程学院,安徽合肥230009;合肥工业大学食品科学与工程学院,安徽合肥230009【正文语种】中文【中图分类】O657.1;S951.4葡萄糖氧化酶(GOx)作为识别原件对葡萄糖具有高选择性,可在氧的存在下催化葡萄糖氧化成过氧化氢和葡糖酸内酯[1]。
自组装普鲁士蓝膜修饰丝网印刷电极构建高灵敏生物传感器
自组装普鲁士蓝膜修饰丝网印刷电极构建高灵敏生物传感器彭京蒙;储震宇;石磊;金万勤【摘要】在丝网印刷碳电极上,采用层层自组装法制备普鲁士蓝薄膜,同时基于戊二醛交联法在薄膜上固定葡萄糖氧化酶,从而构建一种高灵敏度、低成本的葡萄糖生物传感器.考察组装温度和层数对薄膜形貌的影响.在最佳组装条件35℃和40层下,获得了均匀、连续分布的具有纳米立方颗粒结构的普鲁士蓝薄膜.普鲁士蓝立方结构有利于薄膜催化活性的提高,而戊二醛交联法可有效用于酶的固定并保持酶的活性,从而提高传感器的灵敏度和稳定性.在-0.05 V工作电位下,制备的传感器具有超高的灵敏度(111.834 mA/(mol·L-1·cm2)),宽的线性范围(0~1.2 mmol/L),低的检测极限(1μmol/L),同时具有优良的重复性、稳定性和抗干扰能力.本研究中,普鲁士蓝薄膜的制备及酶的固定简单易行,同时结合丝网印刷技术,可实现葡萄糖生物传感器的批量化制备,具有显著的应用前景.【期刊名称】《南京工业大学学报(自然科学版)》【年(卷),期】2016(038)004【总页数】7页(P39-45)【关键词】丝网印刷电极;自组装法;普鲁士蓝;戊二醛交联法;电化学生物传感器【作者】彭京蒙;储震宇;石磊;金万勤【作者单位】南京工业大学材料化学工程国家重点实验室,江苏南京210009;南京工业大学材料化学工程国家重点实验室,江苏南京210009;南京工业大学材料化学工程国家重点实验室,江苏南京210009;南京工业大学材料化学工程国家重点实验室,江苏南京210009【正文语种】中文【中图分类】O614葡萄糖作为生物体内重要的供能物质,与人类的日常生活息息相关。
对葡萄糖的检测,在食品工业中的质量监测、化工发酵过程的控制及糖尿病病情诊断有着重要的意义[1]。
葡萄糖的传统检测方法有光学法和电化学法。
其中,电化学法中的酶电极法因具有高的灵敏度、优良的选择性和操作简便等优点受到广泛关注。
高效阴离子交换色谱积分脉冲安培法测定蓝藻细胞培养液中的蔗糖和甘油葡糖苷
高效阴离子交换色谱积分脉冲安培法测定蓝藻细胞培养液中的蔗糖和甘油葡糖苷梁文辉;法芸;王明林【摘要】建立了一种测定蓝藻细胞培养液中蔗糖和甘油葡糖苷的高效阴离子交换色谱积分脉冲安培检测法。
在最佳的分离条件下,蔗糖和甘油葡糖苷的质量浓度在0.1~50.0 mg/L范围内与色谱峰面积线性良好,线性相关系数r2>0.9999。
蔗糖和甘油葡糖苷的最低检测限分别是0.15 mg/L和0.03 mg/L,测定结果的相对标准偏差小于2%(n=8)。
该方法样品处理简单,无基体干扰,测定的准确度,灵敏度高,可应用于蓝藻培养液中蔗糖和甘油葡糖苷的测定。
%A high performance anion-exchange chromatography with pulsed amperometric detection was developed for the determination of sucrose and glucosylglycerol in cyanobacterial cells. Under the optimized conditions,the concentration of sucrose and glucosylglycerol showed good linearity (r2>0.999 9) with the chromatographic peak area in the range of 0.1–50.0 mg/L. The limit of detection(LOD) was 0.15 mg/L for sucrose and 0.03 mg/L for glucosylglycerol. RSDs of the detection results were less than 2% (n=8). The result showed that the method was convenient and accurate for the determination of sucrose and glucosylglycerol in cyanobacterial cells.【期刊名称】《化学分析计量》【年(卷),期】2014(000)0z1【总页数】4页(P9-12)【关键词】高效阴离子交换色谱;积分脉冲安培检测;蓝藻;培养液;蔗糖;甘油葡糖苷【作者】梁文辉;法芸;王明林【作者单位】山东农业大学,食品科学与工程学院,山东泰安 271018; 中国科学院青岛生物能源与过程研究所,生物燃料重点实验室,山东青岛 266101;中国科学院青岛生物能源与过程研究所,生物燃料重点实验室,山东青岛 266101;山东农业大学,食品科学与工程学院,山东泰安 271018【正文语种】中文【中图分类】O657.7在小分子糖类碳源中,蔗糖可由高等植物通过光合作用直接合成,被认为是自然界最丰富的二糖;同时蔗糖结构简单,很多微生物可以利用,是一种较为理想的碳源。
黑腹果蝇作为指示昆虫快速检测蔬菜中农药残留可行性分析
黑腹果蝇作为指示昆虫快速检测蔬菜中农药残留可行性分析孙丽娟;任士伟;邢小霞;徐丽娟;董向丽【摘要】The toxicity of organophosphorus, carbamate, neonicotinoid, pyrethroid insecticides to Drosophila melanogaster were determined using the method of feeding on toxic medium. The result showed that the tested D. Melanogasterwere very sensitive to pyrethroid and organophosphorus insecticides. After 3h treatment, the LC50 were less than or near to maximum residue limit ( MRL). However, the D. Melanogaster was less sensitive to carbamate and neonicotinoid insecticides. The sensibility of D. Melanogaster to pyrethroid and organophosphorus pesticides mixed in the homogenate of vegetable were future determined, and the same result was obtained. After 3h treatment, the LC50 of DDVP, Chlorpyrifos and Cyfluthrin were 0. 123mg/kg, 0.912mg/kg and 0. 021mg/kg respectively , which were lower than the MRL ( GB ). This experiment indicated that the tested insect D. Melanogaster should be feasible to be used as an indicator to detect pyrethroid and organophosphorus insecticides residues rapidly in vegetables.%采用培养基混毒法,测定了黑腹果蝇(Drosophila melanogaster)对有机磷、氨基甲酸酯、新烟碱类和拟除虫菊酯类杀虫剂的敏感性.结果显示,所试黑腹果蝇对拟除虫菊酯类、有机磷类杀虫剂非常敏感,3h内LC50低于或接近于最大残留限量(MRL);对氨基甲酸酯类杀虫剂敏感性稍差,对新烟碱类杀虫剂不敏感.进一步测定黑腹果蝇对蔬菜匀浆中有机磷类和拟除虫菊酯类杀虫剂的敏感性,结果与培养基混毒法一致,黑腹果蝇保持了对这两类杀虫剂的高度敏感性,3h内敌敌畏、毒死蜱和氯氟氰菊酯的LC50分别是0.123mg/kg、0.912mg/kg和0.021 mg/kg,均低于中国国家标准的最大残留限量.所试黑腹果蝇可以作为指示昆虫用于蔬菜中有机磷类和拟除虫菊酯类杀虫剂残留的快速检测.【期刊名称】《青岛农业大学学报(自然科学版)》【年(卷),期】2011(028)004【总页数】3页(P267-269)【关键词】黑腹果蝇;蔬菜;农药残留;检测【作者】孙丽娟;任士伟;邢小霞;徐丽娟;董向丽【作者单位】青岛农业大学农学与植物保护学院,山东青岛266109;青岛农业大学农学与植物保护学院,山东青岛266109;青岛农业大学农学与植物保护学院,山东青岛266109;青岛农业大学生命科学学院,山东青岛266109;青岛农业大学农学与植物保护学院,山东青岛266109【正文语种】中文【中图分类】X56半个多世纪以来,农药在全世界范围内广泛使用,在保护农作物免受病虫草危害等方面发挥了巨大作用。
阿卡波糖分子结构
阿卡波糖分子结构1. 引言阿卡波糖(Acarbose)是一种用于治疗2型糖尿病的药物,属于α-葡萄糖苷酶抑制剂。
它通过抑制肠道中的α-葡萄糖苷酶,延缓碳水化合物的消化和吸收,从而降低血糖水平。
本文将介绍阿卡波糖的分子结构及其在药物治疗中的作用机制。
2. 阿卡波糖的分子结构阿卡波糖的分子式为C25H43NO18,相对分子质量为645.6 g/mol。
它是一种多羟基醛糖类化合物,具有复杂的环结构。
阿卡波糖由一个葡萄糖基和一个乙醇胺基组成,并通过氧原子与一个丙二醇基相连。
在葡萄糖基上还连接有三个共轭环,其中两个环上含有羟基官能团。
这种特殊的结构使得阿卡波糖具有抑制α-葡萄糖苷酶的活性。
3. 阿卡波糖的作用机制阿卡波糖主要通过抑制肠道中的α-葡萄糖苷酶来降低血糖水平。
α-葡萄糖苷酶是一种能够将碳水化合物分解为葡萄糖的酶,它主要存在于小肠绒毛上皮细胞中。
阿卡波糖通过与α-葡萄糖苷酶结合,形成一个稳定的复合物,从而阻止其对碳水化合物的降解作用。
具体来说,当人体摄入含有淀粉、蔗糖等碳水化合物的食物时,阿卡波糖会在肠道中与α-葡萄糖苷酶结合,并与其竞争性地结合到活性位点上。
这样一来,阿卡波糖就能有效地抑制α-葡萄糖苷酶对碳水化合物的降解作用,减少被吸收进血液的葡萄糖量。
由于阿卡波糖能够延缓碳水化合物的消化和吸收,它可以有效地控制血糖水平的上升。
另外,阿卡波糖还能减少肠道对葡萄糖的吸收,增加肠道内有益菌的生长,改善胰岛素敏感性,从而进一步降低血糖水平。
4. 阿卡波糖的药物治疗应用阿卡波糖是一种口服药物,常用于2型糖尿病患者的治疗。
它主要适用于那些在饮食控制和运动方面未能达到理想效果的患者。
与其他降血糖药物相比,阿卡波糖具有以下特点:•作用持久:阿卡波糖在肠道中起效,并能持续抑制α-葡萄糖苷酶活性,使其具有持久的降血糖作用。
•延缓餐后血糖峰值:阿卡波糖能够延缓碳水化合物的消化和吸收,使餐后血糖峰值降低,减少高血糖的发生。
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3 different electrodes, RSD was 4.43%.
Conclusions
GO nano sheets and MWCNT networks, π–π interaction GOx-MWCNT/GO hybrid composite, electrostatic interactions highly selective and sensitive for glucose determination, over a linear range 0.05–23.2 mM, The limit of detection (LOD) was estimated to be 28 μM. Ks =11.22 s−1 Stability, repeatability and reproducibility This hybrid biocomposite also has a great potential for use in enzyme based glucose biofuel cells.
0.1 ~ 19.82 mM,0.266 μA mM−1, LOD = 0.028 mM
Stability, repeatability and reproducibility
Stability stored in PBS at 4 °C after one month 82% Repeatability 10 successive measurements, RSD about 2.87% Reproducibility
Electrocatalytic property
The possible reaction mechanism of glucose oxidation and oxygen reduction at the composite electrode can be explained:
Amperometric and selectivity
Multiwalled carbon nanotubes (MWCNT) Graphene oxide (GO)
Experimental
ultrasonication water (0.5 mg/ml)
40 mg GO
B
sonicated
3h 40 ml water
5 mg MWNTs
sonicated 10 ml GO 0.5 h 2 h, 500 W
ZetaGO-MWCNT= −35
Rct(bare GCE) Rct(MWCNT/GCE) Rct(MWCNT/GO/GCE)
Raman spectra
激发虚态 h(0 - )
Raman位移 对不同物质:不同
E1 + h0
h0 E1 E0 E0 + h0 h0
对同一物质: 与入射光
Characterization of MWCNT-GO
MWCNT d=30–50 nm hallow tubular structures
GO d=50 nm
ultra thin sheets MWCNT/GO strong π–π interaction
UV–visible spectra
Ks = 11.22 s-1 good biocompatibility, high conductivity
Different pH
shifted towards the negative direction upon increasing the pH 4.0–9.0
This result demonstrates that the redox reaction of GOx at MWCNT/GO/GOx modified electrode belongs to two protons (2H+) and two electrons (2e−) process, as supported by the following equation.
频率无关;表征分子振 - 转
h0
V=1 V=0
h0 +
能级的特征物理量; Raman散射的产生:光电场 E 中,分子产生诱导偶极距 = E ( 分子极化率) 通常非极性分子及基团的 振动导致分子变形,引起 极化率的变化,是拉曼活 性的。
Rayleigh散射
Raman散射 h
拉曼光谱:对与入射光频率不同的散射光谱进行分析, 得到分子振动、转动方面的信息,来研究分子结构。
Introdu(GOx), a flavin enzyme with molecular weight of 150–180 kDa, has been extensively used to monitor the blood glucose levels in diabetics for its catalytic ability to glucose.
However, the realizing of DET between GOx and the electrode is extremely difficult due to the active site of GOx, flavin adenine dinucleotide (FAD), being deeply embedded within a protective protein shell.
Introduction
There have been great challenges in the development of highly sensitive and sophisticated glucose biosensors:
the fabrication of novel multifunctional or homogenous nanofilms with high quality detailed mechanisms explaining the behavior of these nanocomposites on the surface of electrodes enhancing the signal to noise ratio, transduction and amplification of the signals
Contents
• • • • •
Abstract Introduction Experimental Results and discussion Conclusions
Abstract
An amperometric glucose biosensor based on enhanced and fast direct electron transfer (DET) of glucose oxidase(GOx) at enzyme dispersed multiwalled carbon nanotubes/graphene oxide (MWCNT/GO) hybrid biocomposite was developed. The fabricated hybrid biocomposite was characterized by transmission electron microscopy (TEM), Raman and infrared spectroscopy (IR). The TEM image of hybrid biocomposite reveals that a thin layer of GOx was covered on the surface of MWCNT/GO hybrid composite. IR results validate that the hybrid biocomposite was formed through the electrostatic interactions between GOx and MWCNT/GO hybrid composite. Further, MWCNT/GO hybrid composite has also been characterized by TEM and UV–visible spectroscopy. A pair of well-defined redox peak was observed for GOx immobilized at the hybrid biocomposite electrode than that immobilized at the MWCNT modified electrode. The electron transfer rate constant (Ks) of GOx at the hybrid biocomposite was calculated to be 11.22 s−1. The higher Ks value revealed that fast DET of GOx occurred at the electrode surface. Moreover, fabricated biosensor showed a good sensitivity towards glucose oxidation over a linear range 0.05–23.2 mM.The limit of detection (LOD) was estimated to be 28 μM. The good features of the proposed biosensor could be used for the accurate detection of glucose in the biological samples.