电化学检测

Abstract(#br)A simple but robust droplet-based microfluidic system was developed for dose–response enzyme inhibition assay by combining concentration gradient generation method with electrochemical detection method. A slotted-vials array and a tapered tip capillary were used for reagents introduction and concentration gradient generation, and a polydimethylsiloxane (PDMS) microfluidic chip integrated with microelectrodes was used for droplet generation and electrochemical detection. Effects of oil flow rate and surfactant on electrochemical sensing were investigated.

Abstract(#br)This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate.

Disposable Microchip-Based Electrochemical Detector Using Polydimethylsiloxane Channel and Indium Tin Oxide ElectrodeMicrochip;Capillary Electrophoresis;PDMS;ITO;Electrochemical Detection;We have developed a microsystem with a capillary electrophoresis (CE) and an electrochemical detector (ECD). The microfabricated CE-ECD systems are adequate for a disposable type and the characteristics are optimized for an application to the electrochemical detection. The system was realized with polydimethylsiloxane (PDMS)-glass chip and indium tin oxide electrode.

由于受到丰富干扰成分的污染和干扰，直接电化学检测在实际食品样品中仍然具有挑战性。本文报道了一种基于二氧化硅纳米通道和聚二甲基硅氧烷二元组装的电化学传感平台，该平台无需复杂的前处理，即可检测实际食品中的Pb2和Cd2。采用差分脉冲阳极溶出伏安法，电化学检测包括在修饰的硅纳米通道中电沉积金属物种和随后的阳极溶出。在优化条件下，Pb2的线性范围为4 ~ 1500  μg   L-1，Cd2的线性范围为30 ~ 900  μg   L-1。300  μg   L-1的Pb2和Cd2的相对标准偏差分别为2.9 %和3.6 %。无需繁琐的前处理，成功实现了对实际果汁饮料样品中Pb2和Cd2的定量检测，表明研制的传感器对未加工食品具有优良的抗干扰性和实用性。

由于食物中毒增加了人们对公共卫生的兴趣，对一种新的病原体评价监测系统的研究也得到了显著的探索。本研究通过集成基于薄膜的PCR模块、电极模块和基于聚二甲基硅氧烷( PDMS )的手指驱动微流控模块，建立了简单的单片机病原分析系统。采用薄膜式PCR模块和电极模块进行基因扩增和电化学分析，采用PDMS手指驱动微流控模块进行样品迁移和混合，可替代外部泵送系统。集成的无泵微流控芯片包含三个平行的微流控通道，用于同时分析多个样品中的病原体，通道通过按下按钮而无需外部泵浦系统。采用集成无泵微流控芯片，在膜室中采用热循环聚合酶链反应( PCR )方法扩增食源性致病菌的目的基因，并采用方波伏安法对扩增基因进行电化学定量。以大肠杆菌O157：H7为目标病原菌，对其进行敏感评价，检测限( LOD )为10 2个集落形成单位( CFU )，鉴于集成微流控芯片的显著特点，所开发的传感平台可作为一种有前途的病原学筛查工具应用于护理点检测领域。

由于受到丰富干扰成分的污染和干扰，直接电化学检测在实际食品样品中仍然具有挑战性。本文报道了一种基于二氧化硅纳米通道和聚二甲基硅氧烷二元组装的电化学传感平台，该平台无需复杂的前处理，即可检测实际食品中的Pb2和Cd2。采用差分脉冲阳极溶出伏安法，电化学检测包括在修饰的硅纳米通道中电沉积金属物种和随后的阳极溶出。在优化条件下，Pb2和Cd2的线性范围分别为4 ~ 1500μg L - 1和30 ~ 900μg L - 1。300μg L-1的Pb2和Cd2的相对标准偏差分别为2.9 %和3.6 %。无需繁琐的前处理，成功实现了对实际果汁饮料样品中Pb2和Cd2的定量检测，表明研制的传感器对未加工食品具有优良的抗干扰性和实用性。