Solution-based analysis of multiple analytes by a sensor array: Toward the development of an "electronic tongue"
Solution-based analysis of multiple analytes by a sensor array: Toward the development of an "electronic tongue"
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DOI：
10.1021/ja9743405
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发表时间：
1998-07-01
影响因子：
15
通讯作者：
Neikirk, D
中科院分区：
文献类型：
--
作者：
Lavigne, JJ;Savoy, S;Neikirk, D
嗅觉和味觉是由一系列平行发生的特异性和非特异性分子识别事件引起的。1在少数情况下，存在对单个分析物特异的受体。然而，大多数味觉和气味是通过非特异性相互作用的复合反应来识别的。这些感受器的同时反应所产生的模式是特定于一组特定刺激的。例如，哺乳动物的舌头有“味蕾”（图1A）2，它对四种味觉类别作出反应：甜、酸、咸和苦。只有这四种信号的组合，沿着嗅觉信息，为每种促味剂创造了一种独特的模式。嗅觉最近被模仿使用各种不同的转导方案。[3]在一种情况下，当一系列不同的导电聚合物不同地吸附挥发性分子时，“电子鼻”产生的图案是由这些聚合物的电阻率的微小变化引起的。4.溶液相分析的不适用性和对生物相关传感器的最终愿望促使科学家们寻找生物传感系统的替代模拟物。在此，我们描述了一种新的传感器方法，该方法允许同时识别溶液中的多种分析物。微机械加工技术的进步和使用电荷耦合器件（CCD）的高效/快速数据采集与已知的化学指示剂相结合，以创建可以被描述为原始的“电子舌”的单个传感器套件。利用用各种指示剂分子衍生的聚（乙二醇）-聚苯乙烯（PEG-PS）树脂珠6来模拟“味蕾”。这些指示剂对单个分析物具有选择性，但重要的是，它们的识别特性并不特异。为了模拟天然味蕾所在的空腔，我们将树脂珠定位在Si/SiN晶片中形成的微加工威尔斯孔内，从而将珠限制在多组分芯片上的可单独寻址的位置（图1B）。7、8选择威尔斯孔的尺寸，使得它们保持溶胀和未溶胀状态的珠。9为了演示的目的，制作了一个3× 3的珠子阵列，以模拟哺乳动物舌头同时识别各种分析物的能力。通过使用与传感器阵列连接的CCD分析珠的吸收性质来完成信号转导（图1C）。在暴露于分析物时，发现珠的颜色变化在1分钟内完成90%，尽管通常仅需要几秒钟（即，pH变化为3.5秒）。对于每个单独的珠，采集由红色、绿色和蓝色（RGB）光强度组成的数据流。产生的模式存储在计算机中，用于分析物识别和最终量化。在我们的概念验证实验中，将一个特定传感器和三个非特定传感器记录的反应与对照进行比较。的传感器是荧光素的pH值，11 a邻甲酚酞络合剂的钙2+和pH值，11 b茜素络合剂的铈3+，钙2+，和pH值，11 c和最后的硼酸酯的试卤灵衍生的半乳糖单糖。12，13对照是末端胺乙酰化的简单树脂珠。
The sensations of smell and taste result from a series of specific and nonspecific molecular recognition events that take place in parallel. 1 In a few cases there are receptors that are specific for individual analytes. However, most tastants and odorants are identified through a composite of responses from nonspecific interactions. The pattern created by the simultaneous response of these receptors is specific for a particular set of stimuli. For example, the mammalian tongue has “taste buds”(Figure 1A) 2 which respond to four taste catagories: sweet, sour, salty, and bitter. The combination of only these four signals, along with olfactory information, creates a distinct pattern for each tastant. The sense of smell has recently been mimicked using a variety of different transduction schemes. 3 In one case, an “electronic nose” creates patterns that result from small changes in the resistivity of a series of different conducting polymers when the polymers differentially adsorb volatile molecules. 4 The lack of suitability for solution-phase analysis and the ultimate desire to have biologically relevant sensors has driven scientists to search for alternative mimics of biological sensory systems. 5 Herein, we describe a new sensor methodology which allows for the simultaneous identification of multiple analytes in solution. Advances in micromachining techniques and efficient/rapid data acquisition using a charge-coupled device (CCD) were combined with known chemical indicators to create a single sensor suite that may be described as a primitive “electronic tongue”. Poly-(ethylene glycol)-polystyrene (PEG-PS) resin beads6 that were derivatized with a variety of indicator molecules were exploited to mimic “taste buds”. These indicators are selective for individual analytes but, importantly, are not specific in their recognition properties. To mimic the cavities in which natural taste buds reside, we positioned the resin beads within micromachined wells formed in Si/SiN wafers, thus confining the beads to individually addressable positions on a multicomponent chip (Figure 1B). 7, 8 The size of the wells was chosen so that they hold the beads in swollen and unswollen states. 9 For demonstration purposes, a 3× 3 array of beads was created to mimic the capacity of the mammalian tongue to simultaneously identify a variety of analytes. Signal transduction was accomplished by analysis of the absorption properties of the beads using a CCD that was interfaced with the sensor array (Figure 1C). 10 Upon exposure to analytes, color changes for the beads were found to be 90% complete within 1 min, although only seconds were typically required (ie, 3.5 s for changes in pH). Data streams composed of red, green, and blue (RGB) light intensities were acquired for each of the individual beads. The resulting patterns were stored in a computer for analyte identification and ultimate quantification.In our proof of concept experiments, responses recorded at one specific and three nonspecific sensors were compared to a control. The sensors are fluorescein for pH, 11a o-cresolphthalein complexone for Ca2+ and pH, 11b alizarin complexone for Ce3+, Ca2+, and pH, 11c and finally a boronic ester of resorufin-derivatized galactose for simple sugars. 12, 13 The control was simply a resin bead with the terminal amines acetylated.