基于壳聚糖-纳米TiO2复合膜／CdSe固定血红蛋白的过氧化氢生物传感器的研究

以壳聚糖/nano-TiO2复合膜为基底固载量子点硒化镉(CdSe)和血红蛋白(Hb)制备过氧化氢生物传感器.用循环伏安法对修饰电极进行了表征,并用计时电流法对过氧化氢(H2O2)生物传感器的性能进行了研究.结果表明,在优化的实验条件下,该传感器的响应电流与其浓度在3.9×10-6～1.2×10-2mol/L范围内呈良好的线性关系,检出限为1.0×10-6mol/L.该传感器的米氏常数为1.65mmol/L,表明所固定的酶具有较高的生物活性.     

基于电聚合膜／溶胶-凝胶固定酶的葡萄糖传感器的研究

该文以铂电极为基底,电聚合乙酰苯胺作为修饰膜,采用氧化锆溶胶-凝胶法固定酶制备葡萄糖酶传感器.探讨了酶的浓度,溶液的pH值等对电极响应的影响,考察了电极的重现性,干扰及使用寿命.该方法有效的排除了尿酸(UA),抗坏血酸(AA)对测定的干扰.该传感器在葡萄糖浓度8.2×10-6～8.0×10-3mol/L范围内有线性响应,检出限为4.1×10-6mol/L.对葡萄糖有较好的响应特性、稳定性和使用寿命.     

壳聚糖／葡萄糖氧化酶复合膜结合静电自组装技术制备葡萄糖生物传感器的研究

该文利用壳聚糖(chitosan,CS)结合静电自组装方法固定葡萄糖氧化酶(glucose oxidase,GOx)制备了复合膜修饰的酶电极,构建了一种新型的葡萄糖生物传感器,实验结果表明随着(CS/GOx)薄膜层数增加,产生的氧化电流升高,可以通过增加组装次数提高酶电极中GOx的量.实验得到(CS/GOx)6、(CS/GOx)9和(CS/GOx)12响应时间分别为6.4 s、8.5 s和13.0 s,线性浓度范围为7×10-4～1.3×10-2mol/L、4.2×10-4～1.6×10-2mol/L、1.4×10-4～1.9×10-2mol/L.传感器的工作曲线表明增加GOx的层数可以提高传感器的灵敏度,但同时延长了响应时间.     

基于硼掺杂金刚石电极的酚生物传感器的研究

该文研究了以硼掺杂金刚石为基底电极的酪氨酸酶传感器.该酶传感器对酚的催化作用强于以玻碳为基底电极的酪氨酸酶传感器.在浓度为1.0×10-8～1.0×10-5mol/L的范围内传感器对邻苯二酚的响应具有良好的线性关系,检测下限为5.2×10-9mol/L.酶电极的Michaelis-Metent常数(Kapp m)为33.65μmol/L.酶电极对苯酚和对甲苯酚也有良好的响应,线性范围分别为:5.0×10-8～2.0×10-5mol/L、5.0×10-8～5.0×10-6 mol/L.酶传感器有较好的稳定性和重现性.     

基于DNA-Hb修饰的聚合二氧化锆/金电极过氧化氢生物传感器的研究

以聚合二氧化锆(ZrO2)薄膜修饰的金电极为基底,通过在二氧化锆修饰电极表面滴涂DNA和血红蛋白(Hb)溶液制备了性能优良的DNA-Hb/ZrO2/Au过氧化氢传感器.该传感器对H2O2的还原显示出较好的电催化响应,固定在电极表面的Hb在0.1 mol/L(pH5.0)PBS中对过氧化氢响应灵敏度高,检测范围宽(1.7×10-7～3.0×10-3～mol/L),检测下限低(8.0×10-8～tool/L),并且表现出良好的热稳定性和高选择性.     

基于铂纳米线阵列的葡萄糖生物传感器

用电沉积法在聚碳酸酯膜板中制备了铂纳米线阵列,纳米线直径约为250 nm,长度约为2 μm.SEM表征表明,铂纳米线阵列具有均匀有序的结构,纳米线密度为5×108 cm-2.将纳米线阵列薄膜固定到电极表面,研究了修饰电极的电化学行为.在较低电位下(-0.1 V),修饰电极对过氧化氢具有良好的电催化性能,并有较宽的线性响应范围(1×10-7～5×10-2 mol/L).通过戊二醛在电极表面固定葡萄糖氧化酶制备了一种新的葡萄糖传感器.该传感器对葡萄糖的线性响应范围为5×10-6～2×10-3 mol/L,检测下限为1 μmol/L.     

基于聚吡咯纳米阵列的葡萄糖传感器研究

该文以聚碳酸酯为模板,运用电化学聚合法制备了聚吡咯纳米阵列电极,以戊二醛作为交联剂实现了葡萄糖氧化酶在聚吡咯纳米阵列上的稳定固载.通过循环伏安(CV)以及i-t曲线实验研究了基于聚吡咯纳米阵列修饰葡萄糖传感器的电化学性能.实验结果表明,该修饰电极对葡萄糖具有良好的电化学响应,其线性范围为5.0×10-6 mol/L～6.0×10-3 mol/L,检测限为1.0×10-7 mol/L.该传感器具有检测限低、响应速度快、稳定性好等特点,应用于人体血液样品的检测取得了满意的结果.     

纳米银／半胱氨酸修饰葡萄糖生物传感器的研究

为优化电流型生物传感器的性能,采用相转移法结合超声波法制备纳米银溶胶,并用透射电镜对其粒径和形态进行了表征.将纳米银/半胱氨酸与葡萄糖氧化酶(GOD)共同修饰在电极表面制成酶电极.结果表明:制备的纳米银粒子近似球形,平均直径为6.27 nm;酶电极的线性响应范围为5.0×10-5～1.5×10-3 mol/L;检出限为7.14×10-6 mol/L(S/N=3);响应时间小于5 s.4℃保存30 d,该电极仍有83.7%的初始响应电流,重复性和稳定性良好.     

电聚合二氧化锆固载辣根过氧化物酶的第三代生物传感器的研制

利用生物相容性良好的无机材料二氧化锆(ZrO2)对辣根过氧化物酶(HRP)进行直接固定,用交流阻抗法对修饰电极进行了表征,并用循环伏安法和计时电流法对过氧化氢(H2O2)生物传感器的性能进行了研究.结果表明,该法成功的制备了以电聚合ZrO2为载体的无介体第三代电流型生物传感器.其线性范围为1.00×10-6～1.87×10-3mol/L,线性回归方程为:ip(μA)=0.002 3 c(μmol/L)+2.9324,相关系数r为0.996 8,检测限为2.86×10-7 mol/L.     

一种新型的检测阿特拉津的酪氨酸酶传感器的研制

采用自组装的方法制备了酪氨酸酶传感器,运用循环伏安法探讨了该传感器的电化学特性,研究了阿特拉津在该修饰电极上的电化学行为.实验结果表明,阿特拉津在该修饰电极上具有良好的电流响应.阿特拉津在8.7×10-7～8.2×10-5 mol/L范围内,电流与浓度有良好的线性关系,线性方程为,Ip=-0.328c(Atr)+4.414,相关系数为0.9934,检出限为5.4×10-7 mol/L(信噪比为3).     

一种基于纳米金／石墨烯／普鲁士蓝（PB）修饰玻碳电极非标记免疫传感器

采用电聚合的方法将普鲁士蓝（PBl聚合在玻碳电极表面,再将石墨烯修饰在PB上面,然后再采用电沉积的方法将HAuCL直接还原成纳米金粒子,沉积在石墨烯表面,最后将羊抗人IgG抗体直接固定于该修饰的玻碳电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器。利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法对人IgG抗原进行了测定。实验表明,此免疫传感器在含不同浓度人IgG的PBS溶液（pH6．98）中测定,响应电流与人IgG浓度在5．55～455．5ng／mL范围内有良好的线性关系,其相关系数r=0．9926,检测限为0．015ng／mL（S／N=3）。该免疫传感器具有制备简单、响应时间快（5min）、稳定性好等特点。     

Silicon-based microelectrodes for neurophysiology fabricated usinga gold metallization/nitride passivation system

The multimicroelectrode probe (microprobe) is a device used in neurophysiology to record signals from nerve cells. Microprobes typically have a number of gold recording sites supported on a narrow cantilever beam which is inserted into the tissue. Conducting tracks connect the recording sites to bonding pads on the body of the device. The metallization is insulated, except at the recording sites and bonding pads, by a passivation layer. Boron etch stop techniques can be used to produce narrow cantilever beams upon which recording sites are situated. Previously, polysilicon interconnects were used on microprobes fabricated using boron etch stop techniques, with gold inlaid onto the recording sites using a lift-off technique. This meant that mechanical jigging was required before the final shaping of the probes in potassium hydroxide (or other etch) to prevent the etch from attacking the polysilicon conductors beneath the inlaid gold. The process reported here incorporates a gold metallization layer, in conjunction with a plasma-enhanced chemical vapor deposition (PECVD) nitride passivation layer. Since both these materials etch very slowly in potassium hydroxide, no mechanical jigging, or other steps, need to be taken to protect the front of the wafer during the shaping stage. This simplifies the fabrication of these devices     

Colorimetric immunoassay chip based on gold nanoparticles and gold enhancement

A colorimetric immunoassay chip has been developed based on gold nanoparticles for indicating the antibody–antigen binding activity and gold enhancement for amplifying the specific binding signal. Our investigations showed that the results of immunoassay can be represented by the level of color intensity. They were easily observed by a regular camera or naked eye, which is not needed of sophisticated laboratory equipment. Optimization of experimental conditions was carried out and the colorimetric detection had been compared to the standard chemifluorescent detection. Under the optimized conditions, colorimetric immunoassay chip had been demonstrated to detect different amount of immobilized antigens, i.e., human IgG. The results, i.e., color intensity, were mapped to the concentration of immobilized antigens in a dynamic range of 1–5,000 ng/ml. The proposed detection method does not require any sophisticated optical systems; therefore, it is possible to be miniaturized and integrated into a microfluidic system for developing a portable immunoassay device.     

Performance evaluation of a curved electrode actuator fabricated without gold/chromium conductive layers

Microsystem Technologies - Curved electrode actuators displace on the order of a biological cell diameter at low actuation voltages, making them a potential candidate for probing and...     

复杂金精矿焙烧预氧化-氰化提金工艺研究

某富含砷复杂金精矿主要金属矿物为黄铁矿和毒砂,占金属矿物含量的98.19%。金主要以微粒金和超显微金形态存在,常规氰化时浸出率只有40%。通过固定床两段焙烧、固定床常规一段焙烧、间断式沸腾焙烧和连续式沸腾焙烧试验等一系列焙烧预氧化-氰化提金工艺试验,发现固定床两段焙烧是处理该精矿的最佳工艺选择。在一段焙烧温度500℃、焙烧时间1 h、充气氧含量3%和二段焙烧温度650℃、焙烧时间1 h、充气氧含量21%条件下,金浸出率可达91.40%。     

Fabrication of novel chitosan nanofiber/gold nanoparticles composite towards improved performance for a cholesterol sensor

A novel amperometric cholesterol biosensor was fabricated by the immobilization of ChOx (cholesterol oxidase) onto the chitosan nanofibers/gold nanoparticles (designated as CSNFs/AuNPs) composite network (NW). The fabrication involves preparation of chitosan nanofibers (CSNFs) and subsequent electrochemical loading of gold nanoparticles (AuNPs). Field emission scanning electron microscopy (FE-SEM) was used to investigate the morphology of CSNFs (sizes in the range of ∼50-100 nm) and spherical AuNPs. Cyclic voltammetry, hydrodynamic voltammetry and amperometry were used to examine the performance of CSNF-AuNPs/ChOx biosensor. The CSNF-AuNPs/ChOx biosensor exhibited a wide linear response to cholesterol (concentration range of 1-45 μM), good sensitivity (1.02 μA/μM), low response time (∼5 s) and excellent long term stability. The combined existence of AuNPs within CSNFs NW provides the excellent performance of the biosensor towards the electrochemical detection of cholesterol.     

Low cost SU-8 lift-off process to fabricate a gold/glass microelectrodes array for culturing applications

Microsystem Technologies - In this paper, a procedure to release SU-8 layers from glass substrates using typical undesirable effects is described. The proposed process can be used as lift off or...