Amperometric biosensor based on D-aminoacid oxidase for the R-perindopril assay

A new amperometric biosensor based on D-aminoacid oxidase is described for the assay of R-perindopril. R-perindopril can be determined in the 400–¶20 nmol/L concentration range; the detection limit is ¶10 nmol/L. The selectivity was checked with S-perindopril, D- and L-proline, and polyvinylpyrrolidone. The main interfering species was D-proline. An automated system for the assay of R-perindopril based on the concept of flow injection with an amperometric biosensor (based on D-aminoacid oxidase) as detector is also described. The system is suitable for the on-line monitoring of R-perindopril at a sampling rate of 72 samples/h, in the linear range: 100 nmol/L –20 nmol/L with an RSD better than 0.09% (n = 10).     

Simultaneous determination of creatine and creatinine using amperometric biosensors

In order to determine creatine and creatinine amperometric biosensors were proposed. A bienzymatic biosensor based on creatinase (CI) and sarcosine oxidase (SO) was used for the assay of creatine and a trienzymatic biosensor based on CI, SO and creatininase (CA) for the assay of creatinine. The linear concentration ranges are of pmol l⁻¹ to nmol l⁻¹ magnitude order, with very low limits of detection. The biosensors proved high reliability for determination of creatine and creatinine as raw material, and in the pharmaceutical formulation.     

Simultaneous detection of S and R captopril using sequential injection analysis

A simultaneous detection sequential injection analysis (SIA) system is proposed for the determination of S and R captopril using a potentiometric, enantioselective membrane electrode based on maltodextrin (DE=14-17) for the assay of S-captopril and an amperometric biosensor for the assay of R-captopril. The proposed SIA system can be utilized reliably for the on-line simultaneous detection of the enantiomers in the synthesis process at a rate of 38 samples per hour in the following linear concentration ranges: 100-1000 nmol/l (R-captopril) and 1-1000 mumol/l (S-captopril) with a RSD better than 0.009% (n=10).     

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

利用纳米金(Au NPs)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Au NPs-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,p H6.0)中,-0.45 V(vs.Ag/Ag Cl)电位下电流法检测葡萄糖含量,线性检测范围为0.01~0.88 mmol/L,灵敏度为22.54μA·mmol-1·L·cm-2,检出限为1.01μmol/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。     

Simultaneous Determination of Creatine and Creatinine using Monocrystalline Diamond Paste–Based Amperometric Biosensors

Abstract

In order to determine creatine and creatinine, amperometric diamond paste biosensors were proposed. A bienzymatic biosensor based on creatinase and sarcosine oxidase was used for the assay of creatine and a trienzymatic biosensor based on creatinase, sarcosine oxidase, and creatininase was proposed for the assay of creatinine. The linear concentration ranges are of fmol/L magnitude order, with very low limits of detection. The biosensors proved to be highly reliable for determination of creatine and creatinine as raw materials in pharmaceutical formulations as well as in serum samples.     

Nanomolar Detection of Glutamate at a Biosensor Based on Screen-Printed Electrodes Modified with Carbon Nanotubes

The amperometric glutamate biosensor based on screen-printed electrodes containing carbon nanotubes (CNT), and its integration in a flow injection analysis system, is described herein. The sensor was fabricated by simply adsorbing enzyme glutamate oxidase (GlutOx) on a commercial substrate containing multi-wall CNT. The resulting device displayed excellent electroanalytical properties toward the determination of L-glutamate in a wide linear range (0.01-10 μM) with low detection limit (10 nM, S/N≥3), fast response time (≤5 s), and good operational and long-term stability. The CNT modified screen-printed electrodes have a potential to be of general interest for designing of electrochemical sensors and biosensors.     

Ceramic Carbon/Polypyrrole Materials for the Construction of Bienzymatic Amperometric Biosensor for Glucose

Amperometric enzymatic biosensors have high selectivity and simplicity in use. It has advantages over other analytical methods in biochemistry, pharmacology, so it evokes strong interests1,2. Generally, the detection mode involved in oxidase based biosensors is often based on the electrochemical detection of hydrogen peroxide directly3,4. However the direct oxidation of hydrogen peroxide requires a relative high working potential (exceeding ca. 0.6 V vs. SCE), at which many biological sub…     

l-Glutamate biosensor for estimation of the taste of tomato specimens

An amperometric biosensor has been developed for measurement of Umami, or the taste based on the amount of L-glutamate, in tomato foods. The biosensor is based on an enzyme-mediator system in which L-glutamate oxidase is used for biochemical oxidation of L-glutamate and a tetrafulvalene-tetracyanoquinodimethane (TTF-TCNQ) paste, prepared from the mixture of TTF-TCNQ salt, graphite powder, and silicone oil, serves as the mediator. The limit of detection, calculated by use of a four-parameter logistic model, was 0.05 mmol L(-1), and the limit of quantification was 0.15 mmol L(-1). The correlation coefficient (R2) was 0.990 and the relative standard deviation was no more than 1% (n=5). The response time (tau (95)) was 20-50 s, depending on concentration. The repeatability of the sensor was better than 5% (n=10). The sensor developed was stable for more than ten days.     

β沸石固定酶修饰四氰基醌二甲烷电流型葡萄糖传感器的研究

本文介绍了一种新型的酶传感器, 首次以具有一定规整结构的β沸石固定酶, 以7, 7', 8, 8'-四氰基醌二甲烷作为电子传递媒介体,研制成葡萄糖传感器, 运用傅利叶变换红外光谱研究了β沸石与葡萄糖氧化酶之间的相互作用, 通过载体孔径分布和等电点的测定, 研究了载体的孔结构及表面酸性质对酶吸附的影响规律, 并对电极的制备条件和响应性能进行了优化。     

Colorimetric multiplexed immunoassay using specific aggregation of antigenic peptide-modified luminous nanoparticles

Two amperometric enzyme biosensor systems, based on glycerol dehydrogenase/diaphorase (GDH/DP) and glycerol kinase/glycerol-3-phosphate oxidase/peroxidase (GK/GPOx/HRP), were developed and used for estimation of glycerol content in a complex biological fluids. Enzymes were immobilized on interchangeable membranes by PCS-prepolymer technique. Buffers containing ferricyanide/NAD⁺ or ferrocyanide/ATP were used for measurements with GDH/DP and GK/GPOx/HRP biosensor, respectively. FIA assay of glycerol biosensor was characterized by a linear range of 0.01-1 or 0.01-1.5 mM glycerol, sensitivity of 6.02 or 1.42 mA/M cm² and with signal loss of 40% after 90 h or 30% after 16 h during continuous operation at a sample throughput of 10 injections/h for GDH/DP or GK/GPOx/HRP biosensors, respectively. Both biosensors were successfully used for off-line monitoring of glycerol during microbial transformation of glycerol to 1,3-propanediol using an automatized flow-through system. The results were consistent with those obtained with HPLC. The stability of described biosensor systems was sufficient for monitoring and control of fermentation process within 24 h. The storage stability of enzyme membranes was several months.     

全血尿酸生物传感器的研制及临床应用

研制了一种利用全血来测试尿酸含量的安培型生物传感器。采用铁氰化钾作为媒介体,将尿酸氧化酶固定在羧甲基纤维素钠处理过的碳电极表面,研制成一种尿酸生物传感器。该传感器在恒电位0.3V和尿酸氧化酶的催化作用下,使被检测物尿酸氧化,铁氰化钾还原,在电极表面产生氧化-还原峰,利用安培法可对尿酸进行间接测定。该传感器经临床测试,尿酸的测定范围可达25~200mg/L,10s内即可达到稳态电流,测试结果的线性范围较好,相关系数为0.9987。另外,尿酸传感器具有好的抗干扰性,测试精度高、重复性好,RSD<2%。     

Hydrogen peroxide biosensor based on electrodeposition of zinc oxide nanoflowers onto carbon nanotubes film electrode

A new amperometric biosensor for hydrogen peroxide was developed based on adsorption of horseradish peroxidase at the glassy carbon electrode modified with zinc oxide nanoflowers produced by electrodeposition onto multi-walled carbon nanotubes （MWNTs） film. The morphology of the MWNTs/nano-ZnO electrode has been investigated by scanning electron microscopy （SEM）, and the electrochemical performance of the electrode has also been studied by amperometric method. The resulting electrode offered an excellent detection for hydrogen peroxide at -0.11 V with a linear response range of 9.9×10^-7 to 2.9×10^-3 mol/L with a correlation coefficient of 0.991, and response time 〈5 s. The biosensor displays rapid response and expanded linear response range, and excellent stability.     

Xanthine Biosensor Based on Didodecyldimethylammonium Bromide Modified Pyrolytic Graphite Electrode

ＩｎｔｒｏｄｕｃｔｉｏｎＯｒｄｅｒｅｄｆｉｌｍｓｏｆｗａｔｅｒ ｉｎｓｏｌｕｂｌｅｓｕｒｆａｃｔａｎｔｓｃａｎｂｅｐｒｅｐａｒｅｄｂｙｃａｓｔｉｎｇｔｈｅｉｒｓｏｌｕｔｉｏｎｓｏｒｄｉｓｐｅｒｓｉｏｎｓｏｎｔｏａｓｏｌｉｄｓｕｐｐｏｒｔ .1Ｅｖａｐｏｒａｔｉｏｎｏｆｔｈｅｓｏｌｖｅｎｔａｆｔｅｒｃａｓｔｉｎｇｌｅａｖｅｓｔｈｉｎｆｉｌｍｓｅｌｆ ａｓｓｅｍｂｌｅｄｉｎｔｏｏｒｄｅｒｅｄｓｔａｃｋｏｆｂｉ ｌａｙｅｒ ,ｗｈｉｃｈｉｓｓｉｍｉｌａｒｔｏｂｉｏｌｏｇｉｃａｌｍｅｍｂｒａｎｅｆｏｒｍｅｄｂｙ…     

基于等离子体聚合膜固定酶的H2O2生物传感器

以玻碳电极为基础电极,用微波等离子体技术聚合沉积聚乙二胺等离子体膜,使之形成带氨基功能团的表面,再通过戊二醛交联共价固定辣根过氧化物酶,制得H2O2生物传感器.探讨了等离子体聚合膜的形成条件(如放电功率、单体流速、单体气压和聚合时间),讨论了工作电位、介体浓度和pH值对传感器响应的影响.此外,用红外光谱对等离子体聚合膜进行了表征.该传感器在5×10-7～1.1×10-3mol/LH2O2浓度范围内有线性响应,最低检测限为0.3μmol/L.将此传感器用于实际试样回收率的测定,结果良好.     

基于表面重建螺旋型铂铱电极的葡萄糖生物传感器

通过对螺旋型铂铱电极表面进行化学腐蚀和电化学沉积铂纳米粒子实现电极表面的重建和优化,研究了螺旋型铂铱电极在不同腐蚀时间和电沉积时间下的形貌及对过氧化氢(H2O2)的催化活性.对表面重建的工作电极涂覆氧化酶和半透膜,制备出了铂纳米粒子/葡萄糖氧化酶/环氧聚氨酯酶电极,并将其用作葡萄糖传感器的工作电极.传感器计时电流检测结果表明,表面重建后的酶电极传感器对葡萄糖的检测范围扩大为2~45 mmol/L,优于裸铂铱酶电极传感器,电流响应值和灵敏度得到明显提升,同时传感器还具有良好的稳定性和选择性.     

流动注射化学发光植物组织传感器测定草酸盐

草酸是尿道结石主要成因之一 .统计结果表明 ,90 %以上结石均含草酸钙 .回肠病、口角性肠胃炎及脂肪吸收不良均可引起尿液中草酸的增加 .草酸盐的测定在临床上具有重要意义 .微量草酸测定的传统方法是变色酸比色法或偶氮化合物比色法[1 ] .测定草酸盐的方法还有原子吸收光谱法[2 ] 、高效液相色谱法[3] 、离子色谱法[4] 、光度法[5] 和草酸氧化酶法[6] 等 .这些方法或操作复杂、耗时 ,或灵敏度低 ,使其应用受到限制 .本文提出一种测定草酸盐的新方法 ,其原理为草酸 +Ｏ2草酸氧化酶 ＣＯ2 +Ｈ2 Ｏ2 ,Ｌｕｍｉｎｏｌ+Ｈ2 Ｏ2 ｈｖ　　将含有草…     

Amperometric Immunosensor for the Determination of 2′,3′-dideoxyinosine

Abstract

An amperometric immunosensor, based on carbon paste impregnated with solubilized antidideoxyinosine (from rabbit lyophilized powder, whole antiserum) has been constructed for the assay of anti-HIV agent dideoxyinosine (didanosine, DDI). The amperometric immunosensor was reliably used for dideoxyinosine assay in the 900 pmol/L to 9 nmol/L concentration range, with a detection limit of 180 pmol/L, at E = +1.04 V vs. Ag/AgCl. The construction of the immunosensor is reproducible. Its surface can be easily renewed by simple polishing on an aluminium paper. The new amperometric immunosensor is reliable for the assay of 2′,3′-dideoxyinosine in raw material as well as in its pharmaceutical formulation (Videx tablets).     

Graphene/Poly(vinylferrocene) Composite Based Amperometric Biosensor for L‐lysine Determination

A novel and sensitive amperometric biosensor for L‐lysine determination based on a glassy carbon electrode (GCE) modified with graphene (GR) and redox polymer poly(vinylferrocene) (PVF) was constructed. L‐lysine‐α‐oxidase was immobilized onto the modified GCE by a glutaraldehyde/bovine serum albumin cross‐linking procedure. SEM, CV and EIS were used for the characterization of the surface morphology and stepwise fabrication processes of PVF/GR composite. Optimal composition of the biosensor and experimental conditions that affect the performance of the biosensor are discussed. The effect of buffer pH on biosensor response was studied in detail over a wide pH range. L‐lysine biosensor displayed a linear range of 9.9×10⁻⁷ ‐ 3.1×10⁻⁴ M with a low detection limit of 2.3×10⁻⁷ M and K_M ^app value of 0.4 mM. The L‐lysine biosensor was tested using pharmaceutical sample and cheese with satisfactory results.     

蜘蛛丝素和聚乙烯醇固定葡萄糖氧化酶 制备葡萄糖传感器

用蜘蛛丝素和聚乙烯醇的混合材料把葡萄糖氧化酶固定在氧电极表面,制成葡萄糖氧化酶电极。传感器对葡萄糖有灵敏的响应,平均响应时间为20s,电位变化值与葡萄糖浓度在3.0×10     

Development of Amperometric Glucose Biosensor Based on Reconstitution of Glucose Oxidase on Polymeric 3‐Aminophenyl Boronic Acid Monolayer

An amperometric biosensor for determining glucose based on deflavination of the enzyme glucose oxidase and subsequent reconstitution of the apo‐protein with a complexed flavin adenine dinucleotide (FAD) monolayer is described. The GOx‐reconstituted electrode exhibited excellent electrocatalytic activities towards the reduction and oxidation of hydrogen peroxide as well. The prepared biosensor showed an excellent performance for glucose at +0.5 V with a high sensitivity (5.94 μA/mM) and relatively good response time (～12 s) in a wide concentration range of 1–17 mM (correlation coefficient of 0.9998). The applicability to blood analysis was also evaluated.