基于纳米金修饰丝网印刷电极的乙醇生物传感器

在丝网印刷电极上利用吸附法固定乙醇脱氢酶,并用纳米金进行修饰,以铁氰化钾为介体制作了用于酒精检测的一次性乙醇脱氢酶电极试纸.纳米金颗粒修饰酶电极,极大地改善了电极电流响应,提高了传感器的灵敏度.此乙醇传感器的响应时间仅为25 s,灵敏度为0.06 μA(mmol/L)~(-1),线性浓度测量范围为1.0 mmol/L至10 mmol/L.     

多参数血液分析型生物传感器的研究

研制了一种基于叉指阵列(interdigital array ;IDA)薄膜电极的血液分析型医用多参量测量的生物传感器.利用光刻等微加工技术在玻璃基底上制备四个IDA微金电极,电极薄膜以铬为粘附层,金膜厚250nm,finger电极宽和间距均为10μm.工作区中的微电极上分别固定上不同的酶,通过检测"发生-收集"模式下的IDA微电极上生化反应所产生的微电流分别测试血液中血糖,胆固醇,酮体和乳酸浓度.     

LOD酶电极的临床应用研究

研制一种测定乳酸的生物传感器.乳酸氧化酶(LOD)通过共价键固定在尼龙网上制备乳酸氧化酶膜,制得的酶膜固定在流动注入式氧电极上构成流动注入式LOD酶电极.在酶膜上覆盖透析膜限制乳酸扩散,改善传感器响应的线性范围,以符合临床血乳酸检测要求.该传感器对血样测试的结果与常规酶(LDH)光学测定法比较,经统计学分析,两者无差异.结果显示,该LOD酶电极用于临床血乳酸的检测具有可行性.     

纳米金修饰铂金电极固载白喉抗原免疫传感器的研究

该文报道了一种制作电流型白喉抗原免疫传感器的方法.用金纳米颗粒吸附白喉抗原,采用聚乙烯醇缩丁醛(PVB)为辅助固定抗原膜基质将其固定在铂金电极的表面,制成白喉抗原免疫传感器.根据抗原抗体特异性结合形成的免疫复合物使电极敏感膜有效扩散面积减小,电流减少的特性,实现对白喉抗体的定量检测.该传感器对白喉抗体检测的线性范围是2...     

快速检测大肠杆菌O157:H7的电化学阻抗免疫生物传感器

建立了一种采用电化学阻抗谱技术快速检测大肠杆菌O157∶H7的生物传感器,它是通过石英晶体金电极表面附着一层蛋白A膜来固定抗体的。该生物传感器采用了三电极系统-工作电极石英晶体金电极、Ag/AgCl/Cl-SAT参考电极和铂对电极。和以往的普通金电极不同,第一次采用了石英晶体金电极。试验结果说明抗体的固定以及大肠杆菌O157∶H7与抗体的结合都增加了石英晶体金电极表面的电子传递阻抗,在[Fe(CN)6]3-/4-氧化还原对存在的情况下,用电化学阻抗谱测量该阻抗。该免疫生物传感器的检测限是103cfu/mL,石英晶体金电极的电子传递阻抗变化值和大肠杆菌O157∶H7的浓度在一定范围内呈线性关系,检测时间少于10 min。     

基于电化学还原氧化石墨烯的电化学DNA生物传感器

使用还原氧化石墨烯(rGO)制备一种简单、快速和可重复方法构建DNA生物传感器。将带负电的氧化石墨烯(GO)与半胱氨酸上带正电的氨基基团通过静电作用相互吸附,用线性扫描伏安法(LSV)电化学还原电极表面吸附的GO。将二茂铁标记的DNA(Fc-DNA)探针固定到r GO表面,成功构建DNA传感器。传感器的制备过程使用循环伏安法和拉曼光谱表征。通过杂化前后DNA传感器所展现出方波信号峰电流的差异,实现对目标DNA的定量检测。实验结果表明:目标DNA浓度在1. 0×10~(-13)～1. 0×10~(-6)mol/L范围内,峰电流变化与目标DNA浓度呈线性关系,线性相关系数为0. 981,检测限是2. 0×10~(-13)mol/L (S/N=3)。     

一种新型唾液sIgA电流型纳米免疫生物传感器的制备

通过层层自组装,将硫堇(Thi)和纳米金(GNPs)修饰到Nation修饰的玻碳(GCE)电极表面,利用纳米金单层吸附唾液分泌性免疫球蛋白A(sIgA),最后用辣根过氧化物酶(HRP)封闭电极上的非特异性吸附位点,构建了一种检测唾液sIgA的新型电流型纳米免疫生物传感器.该生物传感器灵敏度高,特异性好,测试方便,检测线性范围为6.5-300mg/L,检出限为3.0mg/L;电流值达到95%稳态时间小于20s.探讨了抗体和底物浓度,pH值和温度,孵育时间,干扰物对传感器的影响.该传感器与ELISA法相关性良好(R=0.98932,P<0.001),可用于唾液sIgA的快速、准确检测,从而判断人体局部免疫状况.     

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.     

Nafion-二茂铁修饰的脑疲劳检测生物传感器的研究

通用Nafion固定二茂铁(Fc)作为电子传递体,通过明胶包埋法将葡萄糖氧化酶(GOD)和α-糖苷酶(GA)修饰在Nafion-二茂铁修饰的玻碳电极上,制成检测脑疲劳标志物—唾液淀粉酶的生物传感器。结果表明:该传感器表现出良好的特异性、敏感性、准确性,传感器响应电流与淀粉酶浓度在50～820U/L之间呈现良好的线性关系,检出限为17.5U/L,达到95%稳态响应时间不超过30s。探讨了pH、温度及其他干扰物质等对淀粉酶生物传感器的影响。将此传感器用于唾液中淀粉酶的测定,取得了满意的结果。     

多壁碳纳米管半乳糖生物传感器研究

以普鲁士蓝(PB)膜玻碳电极为基质,用多壁碳纳米管固定半乳糖氧化酶(GAO),构造了半乳糖电流型传感器,研究了半乳糖氧化酶在此传感器中的催化反应机理,对多壁碳纳米管半乳糖传感器的检测条件进行了优化。确认其对半乳糖具有灵敏的生物响应性,表现出良好的线性和分辨力。此传感器对半乳糖摩尔浓度0.5×10-4~1.5×10-2mol/L呈线性响应,检出限为1.0×10-4mol/L,响应时间为10 s,30 d后,响应电流依然保持80%。     

基于应用于生物传感器的新型有机-无机杂化材料

制备了一种应用于生物传感器的新型有机-无机杂化材料,这种杂化材料由二氧化硅溶胶和聚乙烯醇接枝巯基乙酸组成。此杂化材料克服了普通溶胶凝胶容易脆裂的特点,杂化材料中的巯基可以与金原子形成牢固的配位键从而使杂化材料很好地附着在金电极表面。对杂化材料进行了红外光谱、石英电子微天平、原子力显微镜分析。为了检验杂化材料的应用效果,以此杂化材料作为包埋材料在金电极上制备了葡萄糖氧化酶电极。研究了此酶电极的响应速度和稳定性,结果表明此酶电极具有较快的响应速度(响应时间为2.2s)、较好的稳定性(响应电流在70d后衰减9.6%)。     

一种用于集成电化学生物传感阵列的高灵敏度 读出电路的研究

一种用于自组装膜生物传感阵列的高灵敏度信号读出电路包含一个高灵敏度电流读出放大器,可以接受pA-nA范围的输入电流,其电流增益大约60 dB,相位裕度为63°,并在同一输入电流信号的条件下,负载在一个较大的范围变化时,其输出电流几乎几乎是一个常数.芯片采用1.2μm CMOS工艺加工,测试结果表明,该芯片的输出电流对输入电流具有较好的线性度.这种新型电路与标准CMOS工艺兼容,可实现集成的生物传感阵列.     

一种低噪声的生物微传感器CMOS读出电路研究

为提高生物微传感器的探测灵敏度,设计了一种低噪声的生物微传感器CMOS读出电路,提出了一种新型的相关双采样(CDS)电路.对读出电路的噪声进行抑制.在0.6μm CMOS工艺下,用Spectre仿真器对该电路进行了模拟,仿真结果表明,采用相关双采样的CMOS读出电路使传感器的输入输出转换具有良好的线性关系.     

一种葡萄糖氧化酶安培传感器研究

利用铁氰化钾作为电化学反应的媒介体,将葡萄糖氧化酶固定在羧甲基纤维素处理的碳电极表面,制成了一种新型的葡萄糖安培传感器.该传感器在恒电位0.4 V和葡萄糖氧化酶的催化作用下,使被检测物--葡萄糖--氧化,铁氰化钾还原,在电极表面产生灵敏氧化-还原峰,利用安培法可对葡萄糖进行间接测定.葡萄糖的测定范围为2.7～27 mmol/L,线性范围较好,拟合系数为0.997 8,灵敏度较当前葡萄糖传感器有明显的提高,11 s内即可达到输出稳态电流.同时该传感器对葡萄糖的测定避免了常规电化学传感器测定中样品所含大量的易氧化物质--如抗坏血酸和尿酸--带来的干扰.     

基于微阵列生物传感器的CMOS恒电位仪的设计

针对1×4的生物传感器阵列,设计了一种CMOS恒电位仪电路。采用了一种所有运算放大器共享同一运放的左半边电路的恒电位仪结构,极大地减少了读出电路的功耗与芯片版图的面积。在0.6μm CMOS工艺下,用Spectre仿真器对该电路进行了模拟,仿真结果表明：运用该恒电位仪的电流积分电路使传感器的输入输出转换具有良好的线性关系和较宽的动态响应范围。     

Alcohol consumption detection through behavioural analysis using intelligent systems

We describe in this paper a new methodology for blood alcohol content (BAC) estimation of a subject. Rather than using external devices to determine the BAC value of a subject, we perform a behaviour analysis of this subject using intelligent systems. We monitor the user’s actions in an ordinary task and label those data to various measured BAC values. The obtained data-set is then used to train learning systems to detect alcoholic consumption and perform BAC estimation. We obtain good results on a mono-user base, and lower results with multiple users. We improve the results by combining multiple classifiers and regression algorithms.     

Design and modeling of 2-D photonic crystals based hexagonal triple-nano-ring resonators as biosensors

Si photonic crystal resonator which comprises of three hexagonal nano-rings has been investigated. A forward-dropped peak at 1536.60 nm proves that the proposed triple nano-ring (TNR) resonator is a good channel drop filter, which makes it a good candidate for nanomechanical sensor applications. In this paper, the application of the TNR structure as a biosensor has been studied. It is realized that the symmetrical resonance output of the TNR resonator enhance its suitability as a biosensor as this characteristic makes sensing multiple biomolecules and corroboration of results at same input frequency possible.     

Low and moderate alcohol doses,psychomotor performance and perceived drowsiness

To investigate the role of alcohol on reaction time, performance errors and perceived drowsiness, 26 subjects were tested on a step input tracking task combined with a divided attention test. In four sessions in which varying amounts of alcohol were consumed it was found that as the mean blood alcohol concentration (BAC) rose from 0 to 0·073%, the number of errors increased significantly. Also, subjects reported being drowsy for at least 3 hours after drinking moderate amounts of alcohol (mean BAC, 0·050 to 0·073%). The results of the study are discussed in relation to alcohol induced driving impairment.     

Analysis of volatile alcohols in apple juices by an electrochemical biosensor measuring in the headspace above the liquid

An electrochemical biosensor was optimised for the analysis of volatile alcohols directly from the gas phase without prior absorption or pre-concentration. The sensor is based on the alcohol oxidase (Pichia pastoris) catalyzed conversion of ethanol and the amperometric detection of the generated hydrogen peroxide. Key part of the three-electrode set-up was a gas-diffusion working electrode (potential: +600 mV vs. Ag/AgCl) that consisted of a porous Teflon membrane coated with a thin platinum layer. Headspace samples were analysed for alcohols and used to derive alcohol concentrations in the liquid phase. The biosensor had a sensitivity of 3.43 μA/mM for ethanol, a response time of 69 s, a linear dynamic range of 0.10-30 mM, a theoretical detection limit (3 < S/N) of 9.9 μM, and a stability of 86% during continuous operation (18 h @ 1 mM ethanol). Using one sensor on three consecutive days, the mean coefficient of variation was 1.3% (three measurements each day @ 10 mM ethanol). Alcohol contents of three apple juices determined with the biosensor were in the range 0.30 g/l-0.67 g/l (equivalent to 6.51 mM-14.5 mM). However, ethanol contents determined by high pressure liquid chromatography coupled to refractive index detection (HPLC-RI) and by a commercial enzyme test kit based on alcohol dehydrogenase ranged from 0.12 g/l to 0.38 g/l (equivalent to 2.60 mM-8.25 mM). Both indicate that the biosensor detected alcohols other than ethanol in the apple juices. HPLC-RI coupled to the biosensor in a flow-through configuration demonstrated that the biosensor detected methanol concomitant to ethanol. Thus, the biosensor could perform a qualitative analysis of the total content of volatile alcohols in apple juices by analysing the gas phase above the sample. This offers the additional advantage that possible, non-volatile interfering substances in the liquid sample cannot impair the measurement.