微流控生物传感器 2011

Separation and simultaneous detection of anticancer drugs in a microfluidic device with an amperometric biosensor.

Biosensors & bioelectronics Chandra P, Zaidi SA, Noh HB, Shim YB
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组成图示

Separation and simultaneous detection... 传感器构成示意图

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传感器类型

微流控生物传感器

检测对象

米托蒽醌(mitoxantrone, MIT)、伊达比星(idarubicin, IDA)、多柔比星(doxorubicin, DOX)、柔红霉素(daunomycin, DAN);样品基质:加标人尿液(spiked human urine)及缓冲液

检测原理

蒽环类抗癌药物具有平面芳香结构,可嵌入双链DNA(dsDNA)碱基对之间,并与心磷脂(CL)发生相互作用,从而在SPE/AuNPs/pTTBA/dsDNA/CL/AuNPs电极表面被识别和富集。药物本身具有电活性,在-700 mV检测电位下发生还原反应,产生与浓度成正比的安培电流。pTTBA导电聚合物和AuNPs改善电子传递,降低电极污染,提高响应稳定性。微流控芯片通过场放大样品堆叠(FASS)和场放大样品进样(FASI)实现预浓缩,结合电泳分离使四种药物依次到达检测端,峰面积随药物浓度增加而增大。FASS与FASI联用可获得约1093倍灵敏度增强。

检测灵敏度

LOD: MIT 1.2 (±0.05) fM;IDA 2.2 (±0.1) fM;DOX 3.6 (±0.2) fM;DAN 5.5 (±0.3) fM;线性范围: MIT 2.0–60.0 pM;IDA 5.0–55.0 pM;DOX 7.5–50.0 pM;DAN 8.0–50.0 pM;R^2: 0.9913–0.9982

效应效果

该装置100 s内完成四种药物分离,迁移时间为50.3±1.8、66.5±2.2、88.0±2.5和98.3±3.8 s。多次进样RSD小于5%,表1响应精度RSD为1.2%–3.6%。与裸SPE相比,修饰探针电流提高10倍以上,浓度增强因子为10121–17050,FASS与FASI联用灵敏度增强约1093倍。加标人尿液中MIT、IDA、DOX和DAN回收率分别为98.4%、95.6%、97.2%和98.0%,RSD小于5%。抗坏血酸、尿酸、对乙酰氨基酚和多巴胺无外峰,抗干扰良好。相比HPLC/CE-LIF等复杂方法,作者认为本方法简单、快速、无需标记、成本低,可用于医院废水和化疗患者体液监测。

传感器的构成

  • 基底/换能器电极:丝网印刷电极(SPE),含碳工作电极、Ag导电层和绝缘墨层,作为低成本可批量制备的电化学换能基底
  • 纳米材料修饰层:金纳米颗粒(AuNPs)电沉积于SPE表面,增强导电性并改善电极响应
  • 导电聚合物修饰层:聚TTBA(pTTBA,5,2′:5′,2′′-terthiophene-3′-carboxylic acid聚合物),提供羧基用于共价固定DNA
  • 识别元件:氨基末端探针DNA(pDNA/ssDNA)经EDC/NHS与pTTBA羧基共价结合,再杂交互补DNA(cDNA)形成双链DNA(dsDNA),用于嵌入结合蒽环类药物
  • 识别元件:心磷脂(CL)吸附于dsDNA表面,模拟癌细胞表面阴离子脂质,增强抗癌药物结合
  • 信号/导电增强层:胶体金纳米颗粒(AuNPs)修饰于CL表面,形成SPE/AuNPs/pTTBA/dsDNA/CL/AuNPs探针,增强电子传递与安培信号
  • 电化学检测系统:Ag/AgCl参比电极、Pt丝对电极和100 mM PBS检测缓冲液,用于恒电位安培检测

中文摘要

本文报道了一种简单且高灵敏度的抗癌药物同时检测方法,通过将预浓缩与分离步骤集成于微流控装置,并结合安培生物传感器实现检测。在分离通道末端,采用双链DNA(dsDNA)和心磷脂(CL)修饰的丝网印刷电极(SPE)进行安培检测。利用场放大样品堆叠(FASS)和场放大样品进样(FASI)技术显著提高预浓缩能力。对影响分析性能的实验参数,如pH、温度、缓冲液浓度、水塞长度和检测电位进行了优化。多次进样可获得可重复响应,相对标准偏差小于5%。校准曲线在2–60 pM范围内呈线性,相关系数介于0.9913和0.9982之间。四种药物的检出限为1.2(±0.05)至5.5(±0.3)fM。该装置在加标真实尿液样品中直接分析抗癌药物得到成功验证,并考察了实际样品中常见化学物质的干扰效应。

英文摘要

A simple and highly sensitive method for simultaneous detection of anticancer drugs is developed by integrating the preconcentration and separation steps in a microfluidic device with an amperometric biosensor. An amperometric detection with dsDNA and cardiolipin modified screen printed electrodes are used for the detection of anticancer drugs at the end of separation channel. The preconcentration capacity is enhanced thoroughly using field amplified sample stacking and field amplified sample injection techniques. The experimental parameters affecting the analytical performances, such as pH, temperature, buffer concentration, water plug length, and detection potential are optimized. A reproducible response is observed during multiple injections of samples with a RSD <5%. The calibration plots are linear with the correlation coefficient between 0.9913 and 0.9982 over the range of 2-60 pM. The detection limits of four drugs are determined to be between 1.2 (± 0.05) and 5.5 (± 0.3) fM. The applicability of the device to the direct analysis of anticancer drugs is successfully demonstrated in a real spiked urine sample. Device was also examined for interference effect of common chemicals present in real samples.