传感器的TAS焊接

本文介绍了采用Ar+H_2混合气体保护自动点焊(TAS焊)新工艺,实现了压力传感器、电感传感器等器件的封装。文中对传感器结构及焊接特点,TAS焊接设备及工艺作了详细的阐述。     

Pb~(2+)生物传感器的研究综述

Pb是有毒致癌重金属,随着水中Pb污染日益严重,对环境和人体健康造成了极大的危害。为了有效地防止Pb污染,近年来发展了一些简单、快速、高效、低成本的Pb2+生物传感器,如比色传感器、荧光传感器、电化学传感器。主要综述了这3种Pb2+生物传感器的研究现状,指出其优缺点,并展望其发展方向。     

智能视频监控系统中的“人工智能+物联网”技术运用研究

“人工智能+物联网”的强强联合可促进视频监控系统智能化升级。从物联网技术的含义出发,分析物联网技术发展现状,阐述传感器与传感器网关、RFID、人工智能、云计算等关键技术,剖析“智能家居”案例中的智能门锁、照明、温控、窗帘控制、监控与安防、家电系统,以期运用“人工智能+物联网”技术加持智能视频监控系统,为人们提供更安全、更舒适、更便捷的工作和生活环境。     

一种新型有机磷液晶传感器

提出了一种新型有机磷液晶传感器,其基底表面仅由Cu2+功能化。将液晶5CB滴凃其上,利用正交偏光显微镜对传感器的光学表征进行观察。传感器的光学表征随时间逐渐从亮转为暗,且其转为全暗态所需的时间与Cu2+的浓度呈反比;当通入甲基磷酸二甲脂(DMMP)气体时,传感器呈现出逐渐从暗到亮的光学表征变化,循环通入空气和DMMP气体时交替出现的暗与亮的光学表征转变显示了其对DMMP的光学响应具有可重复性;另外,水、乙醇、甲苯和丙酮等其他干扰气体的通入则不会引起光学表征的任何变化。同时,在实验范围内(0.1~10mmol/L),Cu2+的浓度越低,传感器对DMMP的光学响应灵敏度越高。结果表明了这种新型有机磷液晶传感器造价低廉,制作过程简易,可选择性、可重复性地应用于如DMMP等有机磷的检测中。     

基于电化学寡核苷酸传感器的痕量汞离子检测

水环境中的重金属汞污染日益严重,对生态环境和人类健康造成了不容忽视的威胁。因此,现场监测痕量汞离子具有极其重要的意义。构建了一种基于胸腺嘧啶-Hg^2+-胸腺嘧啶(T-Hg^2+-T)特异性配位结构的无标记型电化学寡核苷酸传感器,用于检测痕量Hg^2+。将末端修饰巯基的富T寡核苷酸链(Oligo)自组装到金电极表面,当存在Hg^2+时,Oligo探针将捕获Hg^2+而发生构象变化,形成"发卡型"结构。利用电化学阻抗谱对金电极表面自组装膜的构象变化进行表征,发现电子转移阻抗RCT随Hg^2+浓度的升高而减小,建立两者间的线性关系,从而实现对Hg^2+的定量检测。本传感器在0.5 nmol/L^500 nmol/L范围内具有良好线性关系,检出限为0.2 nmol/L,特异性实验表明该传感器对Hg^2+选择性极好。该传感器为水环境中痕量汞离子的准确、定量检测提供了一种有效的手段。     

壳聚糖固定化脲酶生物传感器选择性测定铜离子

基于重金属对脲酶的抑制作用,研制了用于测定铜离子的生物传感器。该生物传感器的制备以壳聚糖为载体,将脲酶固定于pH电极表面。由于壳聚糖对Cu2+的富集,该生物传感器展现出高灵敏度。在样品溶液中加入5 mmol/L NaI,可以消除Hg2+和Ag+的干扰,从而实现Cu2+的选择性检测。在0.005～0.5μg/mL的浓度范围内,脲酶活性的抑制率与Cu2+浓度的对数呈良好的线性响应关系,其检出限为0.002μg/mL。将使用后的生物传感器浸泡于0.5 mmol/L的EDTA溶液再生5 min,被Cu2+抑制的脲酶的活性可以得到恢复。     

高性能荧光猝灭式光纤氧传感器

用钌两价正离子 (Ru2 + )—邻菲咯啉配合物为指示剂 ,研制了一种基于荧光猝灭原理的光纤氧传感器。采用锁相放大技术 ,实现了对弱荧光信号的检测。该传感器具有较高的检测精度、较强的抗干扰能力、较好的重复性和稳定性     

对“八五”期间我国化学传感器发展规划的几点设想

化学传感器是将各种物态(气态、液态及部分固态及粉尘)中的化学物质的组分及含量转变为可测模拟量的器件,现阶段的化学传感器已发展到数百计。可测定各种有害气体(如CO、CH_4、CO_2、O_2、NH_3、Cl_2、H_2S、NO_2及某些军用毒气),无害气体(H_2、O_2等)以及液体中多种电解质离子(如K~+、Na~+、Mg~(2+)、Ca~(2+)、F~-、Cl~-、Br~-、I~-、NO_3~-、CrO_4~(2-)、Pb~(2+)、Cd~(2+)等)以及某些有机物质(如数十种药物),血液及体液中某些化学组分(如葡萄糖、氨基酸)及粉尘中某些化学物质。按其作用机理又可分为电化学式、光学式、磁学式、热学式及质量传感器等类型。化学传感器不同于物理量(如长度、重     

矿井无人驾驶环境感知技术研究现状及展望

矿井辅助运输系统是煤矿企业运输人员和重要物料、装备的必备系统,实现矿井无人驾驶是提高运输效率、保障运输安全的必然要求,也是落实国家煤矿智能化建设部署的必由之路。矿井无人驾驶依赖于准确实时的环境感知,即利用激光雷达、毫米波雷达等车载感知器件和车联网支持下的协同感知,实现车辆局部甚至矿井全局的精确详尽感知。对矿井无人驾驶环境感知技术的研究现状进行了系统梳理,指出巷道特殊环境使得矿井车载感知设备的性能都将出现不同程度的下降,并对各种车载感知设备的优劣进行了总结归纳;详细阐述了矿井无人驾驶环境感知的关键技术,包括基于可见光图像或激光点云的单传感器障碍物识别方法,多传感器融合感知的分类及可见光图像+激光点云、可见光图像+毫米波点云、可见光图像+激光点云+毫米波点云、4D毫米波雷达+其他感知器件等多传感器融合方式,智能网联协同感知的实现方式、数据处理方法及其对无人驾驶的促进作用,井下巷道交通标志检测与识别方法,井下无轨胶轮车和有轨机车的巷道可行驶区域分割方法等;对矿井无人驾驶环境感知技术的发展方向进行了展望,建议提高矿井多传感器融合性能、研究矿井自适应感知算法并突破矿井智能网联协同感知技术。     

声表面波NO_2传感器敏感膜研究进展

由于工业检测、环境监测、医学监测等领域的需求,高性能NO2传感器得到了广泛的研究。声表面波传感器技术的发展为研发高灵敏度、高稳定性、响应快速、小型化的NO2传感器提供了极大的潜能。总结了近30年来声表面波NO2传感器敏感膜的研究现状,并根据现有的研究和传感器的应用需求,深入探讨了声表面波NO2传感器敏感膜面临的挑战和发展趋势。     

Designing of MIP-based QCM sensor for the determination of Cu(II) ions in solution

A novel quartz crystal microbalance (QCM) sensor with a high selectivity and sensitivity has been developed for the determination of Cu(II) ions, based on the modification of Cu(II) ion-imprinted polymer (Cu(II)-IIP) film onto a quartz crystal. The performance of the developed MIP-QCM sensor was evaluated and the results indicated that a sensitive MIP-QCM sensor could be fabricated. The obtained MIP-QCM sensor presents high-selectivity monitoring of Cu(II) ions, better reproducibility, shorter response time (6 min), wider linear range (0.001–50 μM) and lower detection limit (8 × 10⁻⁴ μM). The practical analysis of the MIP-QCM sensor confirms the feasibility of Cu(II) determination in wastewater.     

分布式自适应CMLWCA CFAR 检测方法

针对分布式多传感器系统中不同传感器的信噪比会影响检测决策，提出一种利用各传感器信噪比决定其权值的自适应删除均值加权单元平均（CMLWCA）恒虚警率（CFAR）检测的新方法．在假定目标服从Swerling II起伏的情况下，导出了相应的检测概率与虚警概率闭式解．多种检测器数值分析的比较结果表明了该方法的有效性和优越性．     

Shrink-induced ultrasensitive mercury sensor with graphene and gold nanoparticles self-assembly

Here we report an ultrasensitive trace mercury(II) micro sensor based on heat-shrinkable polymer (polyolefins, PO). The layer-by-layer self-assembly (LBL SA) method was employed to modify mixed gold nanoparticle (Au NPs) and graphene solution on a micro gold electrode with PO substrate. The unique wrinkle structure of the electrode surface and superior properties of modification film enhanced the performance of LBL SA graphene–Au NPs shrink sensor greatly in determination of Hg(II) using anodic stripping voltammetry (ASV): compared with a shrink gold electrode without surface modification, the sensitivity was improved for about 3.7 times from 0.197 to 0.721 μA/ppb; compared with a same-sized sensor without surface modification nor shrink, the sensitivity was improved for over 50 times. This sensor’s detection limit of Hg(II) was achieved as 0.931 ppb with a sensitivity of 0.721 μA/ppb. This simple but highly sensitive sensor can be widely used in applications of on-line environmental monitoring of Hg(II).

     

Simultaneous measurement of Pb, Cd and Zn using differential pulse anodic stripping voltammetry at a bismuth/poly(p-aminobenzene sulfonic acid) film electrode

A novel sensor was developed for simultaneous detection of Pb, Cd and Zn, based on the differential pulse anodic stripping response at a bismuth/poly(p-aminobenzene sulfonic acid) (Bi/poly(p-ABSA)) film electrode. This electrode was generated in situ by depositing simultaneously bismuth and the metals by reduction at −1.40 V on the poly(p-ABSA) modified electrode. Compared with the bismuth film electrode, the Bi/poly(p-ABSA) film electrode can yield a larger stripping signal for Pb, Cd and Zn. Under the optimum conditions, a linear response was observed for Cd and Zn in the range from 1.00 to 110.00 μg L⁻¹ and for Pb in the range from 1.00 to 130.00 μg L⁻¹. The detection limits of Pb(II), Cd(II) and Zn(II) were 0.80, 0.63 and 0.62 μg L⁻¹, respectively. Finally this sensor had been applied to the simultaneous determination of Pb(II), Cd(II) and Zn(II) in river water samples and the results were quite corresponding to the value obtained by atomic absorption spectrometry.     

Selective, simple and economical lead sensor based on ibuprofen derived silver nanoparticles

Lead (Pb) assessment in the environment is highly demanded due to its extreme toxicity associated with many health problems. We synthesized ibuprofen derived silver nanoparticles (Ibu-AgNps) by a simpler method and applied them as excellent voltammetric Pb(II) sensor. Various optimized parameters include, the kind of electrode, concentration of electrolyte, number of drops, deposition potential, stirring rate, nitrogen purging time, initial potential and pH. The fabricated sensor is simple, highly selective, sensitive, stable and reproducible. The sensor works in linear range, 0.1-1500 ppb with lower detection limit (LDL) of 0.01 ppb (∼50 pM) and regression coefficient of 0.999 for Pb(II) ions. RSD of 1.5% was observed for 20 replicates of 1000 ppb Pb(II) solution which proves its excellent reproducibility. No interference was noticed for fabricated sensor by ions commonly found in water. Drinking, tap and river water samples were successfully analyzed for the estimation of Pb(II) ions by the developed sensor.     

Environmentally friendly disposable sensors with microfabricated on-chip planar bismuth electrode for in situ heavy metal ions measurement

This paper presents an environmentally friendly disposable heavy metal ion sensor for in situ and online monitoring in the nature and physiological systems. The miniaturized sensor chip consists of a non-toxic microfabricated bismuth (Bi) working electrode that replaces the conventional mercury electrodes, an integrated Ag/AgCl reference electrode, a gold counter electrode, and microfluidic channels. In this work, the electrochemical behavior of the Bi working electrode was characterized in several non-deaerated buffer solutions using cyclic voltammetry. The detection and quantification of Pb (II) and Cd (II) were statically performed using anodic stripping voltammetry inside the microchannels, in the Pb (II) concentration range of 25–400 ppb (R² = 0.991) with limit of detection of 8 ppb for 60 s deposition, and in the Cd (II) concentration range of 28–280 ppb (R² = 0.986) with limit of detection of 9.3 ppb for 90 s deposition. Particularly, the applications of this sensor chip have been reported with the examples of in situ measurement of Cd (II) concentration in soil pore and ground water and online direct measurement of Cd (II) concentration in cell culture media in its native environment.     

A polymer lab chip sensor with microfabricated planar silver electrode for continuous and on-site heavy metal measurement

This paper presents a reusable polymer lab chip sensor for continuous and on-site heavy metal monitoring in nature. In particular, detection of lead (Pb(II)), which is the most common heavy metal pollutant, has been performed using the proposed lab chip sensor. The miniaturized lab chip sensor consists of a microfabricated silver working electrode that replaces the conventional mercury and bismuth electrodes, an integrated silver counter and quasi-reference electrode, and microfluidic channels. The proposed sensor targets on-site environmental monitoring in a continuous fashion without disturbing or contaminating the sensing environment when it is reused. The reusability of the miniaturized lab chip sensor was characterized through forty-three consecutive measurements in non-deoxygenating standard solutions inside the microchannels using square-wave anodic stripping voltammetry (SWASV). With only 13.5 μL of sample volume the sensor chip showed a correlation coefficient of 0.998 for the Pb(II) concentration range of 1-1000 ppb with the limit of detection of 0.55 ppb at 300 s deposition time. The peak potentials during the forty-three consecutive SWASV measurements showed a relative standard deviation of 1.0%, with a standard deviation of 0.005 V. The high repeatability and linearity of the sensor over the large, three orders of magnitude, dynamic range of 1-1000 ppb showed that the developed sensor chip can be reused for a variety of on-site measurements such as for soil pore water or groundwater, using only micro-volumes.     

Luminescent Eu(III) hybrid sensors for in situ copper detection

In this work we used the sol-gel technique to develop luminescent Eu(III) transparent films deposited on glass slides to build for sensor devices capable of monitoring transition metal ions in aqueous solutions. The films were obtained from a bis(trialkoxysilyl) organic precursor synthesized from the amide of the 2,6-pyridinedicarboxylic acid (DPA) with aminopropyltriethoxysilane (APTES) in the presence or absence of cetyl trimethyl ammonium bromide (CTAB) surfactant as templating agent and triethylethoxysilane (TEOS) as crosslinker. These sensor devices were used to perform in situ quenching experiments by Cu(II), Fe(III), Co(II) and Ni(II) ions. The results indicate that the templated films allow the detection and quantification of these metals down to ppb levels by means of the values of the Stern-Volmer constants. In particular, it was shown that Cu(II) acts as an extremely efficient quencher (K_SV = 3.5 × 10⁵ M⁻¹) when compared with the results obtained for the other metals, opening the possibility to use these devices as potential Cu(II) sensors for actual applications in aqueous media.     

Development of a new fluorescent sensor based on a triazolo-thiadiazin derivative immobilized in polyvinyl chloride membrane for sensitive detection of lead(II) ions

A new sensor membrane based on a novel triazolo-thiadiazin derivative immobilized in polyvinyl chloride has been developed for the determination of Pb(II) ions that displays excellent performance. The parameters involved in the preparation of the optode and determination of Pb(II) were optimized. Under the optimal conditions, the proposed sensor displays a calibration response for Pb(II) over a wide concentration range of 5.0 × 10⁻⁸ to 3.8 × 10⁻⁴ M with the detection limit of 2.2 × 10⁻⁸ M. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity over common metal ions. The optode membrane developed is easily prepared, stable, rapid, and simple for the determination of Pb(II). The accuracy of the proposed sensor was confirmed by analyzing standard reference materials of natural water and surface water. The sensor was successfully used for the determination of Pb(II) ions in water samples with satisfactory results.     

A new optical sensing reaction for nitric oxide

Based on the reaction between the Cu(II) complex of Eriochrome cyanine R (ECR) and nitric oxide (NO) in phosphate buffer (pH 7.4), a new colorimetric method for the determination of NO concentration has been developed. The linear calibration range for NO was 0–60 μM with a detection limit of 1.24 μM. This reaction was then used as the basis in the development of a fibre optic chemical sensor for NO gas. The copper complex was incorporated into silicone rubber membranes and exposed to NO gas after incubating the films in phosphate buffer (pH 7.4). A linear calibration for NO gas between 0 and 6 ppm was obtained with a detection limit of 0.227 ppm (1 μM 0.031 ppm NO in solution). The sensor response was shown to be reproducible and reversible (2.77%, R.S.D., n=4) upon exposure to aqueous phosphate buffer (pH 7.4). The sensor response was also found to be pH independent between 7 and 10.