Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Nanotechnology. 2010 Mar 26;21(12):125503. doi: 10.1088/0957-4484/21/12/125503. Epub 2010 Mar 5.
Conducting polymer-metal nanoparticle hybrids, fabricated by assembling metal nanoparticles on top of functionalized conducting polymer film surfaces using conjugated linker molecules, enable the selective sensing of volatile organic compounds (VOCs). In these conducting polymer-metal nanoparticle hybrids, selectivity is achieved by assembling different metals on the same conducting polymer film. This eliminates the need to develop either different polymers chemistries or device configurations for each specific analyte. In the hybrids, chemisorption of the analyte vapor induces charge redistribution in the metal nanoparticles and changes their work function. The conjugated linker molecule causes this change in the work function of the tethered nanoparticles to affect the electronic states in the underlying conducting polymer film. The result is an easily measurable change in the resistance of the hybrid structure. The fabrication of these sensing elements involved the covalent assembly of nickel (Ni) and palladium (Pd) metal nanoparticles on top of poly(3,4-ethylenedioxythiophene-co-thiophene-3-acetic acid), poly(EDOT-co-TAA), films using 4-aminothiophenol linker molecules. The change in resistance of hybrid Pd/poly(EDOT-co-TAA) and Ni/poly(EDOT-co-TAA) hybrid films to acetone and toluene, respectively, is observed to be in proportion to their concentrations. The projected detection limits are 2 and 10 ppm for toluene and acetone, respectively. A negligible response (resistance change) of the Pd/poly(EDOT-co-TAA) films to toluene exposure confirmed its selectivity for detecting acetone. Similarly, lack of response to acetone confirmed the selectivity of the Ni/poly(EDOT-co-TAA) stacks for detecting toluene. It is anticipated that the assembly of other metals such as Ag, Au and Cu on top of poly(EDOT-co-TAA) would provide selectivity for detecting and discriminating other VOCs.
导电聚合物-金属纳米粒子杂化材料，是通过将金属纳米粒子组装在功能化的导电聚合物薄膜表面上来制备的，利用共轭连接分子，实现了对挥发性有机化合物（VOCs）的选择性传感。在这些导电聚合物-金属纳米粒子杂化材料中，通过在同一导电聚合物薄膜上组装不同的金属来实现选择性。这消除了为每个特定分析物开发不同聚合物化学或器件配置的需要。在杂化材料中，分析物蒸气的化学吸附会导致金属纳米粒子中的电荷重新分布，并改变它们的功函数。共轭连接分子会导致连接的纳米粒子的功函数发生这种变化，从而影响底层导电聚合物薄膜中的电子态。结果是杂化结构的电阻发生了可测量的变化。这些传感元件的制造涉及到使用 4-氨基噻吩连接分子，将镍（Ni）和钯（Pd）金属纳米粒子共价组装在聚（3,4-乙撑二氧噻吩-共-噻吩-3-乙酸）、聚（EDOT-co-TAA）薄膜的顶部。观察到混合 Pd/poly(EDOT-co-TAA) 和 Ni/poly(EDOT-co-TAA) 混合薄膜对丙酮和甲苯的电阻变化与它们的浓度成正比。甲苯和丙酮的预计检测限分别为 2 ppm 和 10 ppm。Pd/poly(EDOT-co-TAA) 薄膜对甲苯暴露的响应（电阻变化）可以忽略不计，这证实了它对检测丙酮的选择性。同样，Ni/poly(EDOT-co-TAA) 叠层对丙酮没有响应，证实了它们对检测甲苯的选择性。预计将其他金属（如 Ag、Au 和 Cu）组装在 poly(EDOT-co-TAA) 顶部，将为检测和区分其他 VOCs 提供选择性。
