Peregrino Priscilla P, Cavallari Marco R, Fonseca Fernando J, Moreira Sanclayton G C, Sales Maria José A, Paterno Leonardo G
Laboratório de Pesquisa em Polímeros e Nanomateriais, Instituto de Química, Universidade de Brasília, Brasília, DF 70904-970, Brazil.
Universidade Federal da Integração Latino-Americana, Engenharia de Energia, Foz do Iguaçú, PR 85866-000, Brazil.
ACS Omega. 2020 Mar 5;5(10):5001-5012. doi: 10.1021/acsomega.9b03892. eCollection 2020 Mar 17.
This work unveils the roles played by potato starch (ST) in the immobilization, photochemical reduction, and gas sensitivity of graphene oxide (GO) films. The ST/GO films are assembled layer by layer (LbL) onto quartz substrates by establishing mutual hydrogen bonds that drive a stepwise film growth, with equal amounts of materials being adsorbed in each deposition cycle. Afterward, the films are photochemically reduced with UV irradiation (254 nm), following a first-order kinetics that proceeds much faster when GO is assembled along with ST instead of a nonoxygenated polyelectrolyte, namely, poly(diallyl dimethylammonium) hydrochloride (PDAC). Finally, the gas-sensing performance of ST/reduced graphene oxide (RGO) and PDAC/RGO sensors fabricated via LbL atop of gold interdigitated microelectrodes is evaluated at different relative humidity levels and in different concentrations of ammonia, ethanol, and acetone. In comparison to the PDAC/RGO sensor, the ones containing ST are much more sensitive, especially when operating in a high-relative-humidity environment. An array comprising these chemical sensors provides unique electrical fingerprints for each of the investigated analytes and is capable of discriminating and quantifying them in a wide range of concentrations, from 10 to 1000 ppm.
这项工作揭示了马铃薯淀粉（ST）在氧化石墨烯（GO）薄膜的固定、光化学还原和气体敏感性方面所起的作用。通过建立相互氢键驱动逐步的薄膜生长，将ST/GO薄膜逐层（LbL）组装到石英基板上，每个沉积循环吸附等量的材料。之后，用紫外线照射（254 nm）对薄膜进行光化学还原，遵循一级动力学，当GO与ST而非非氧化聚电解质即聚（二烯丙基二甲基氯化铵）（PDAC）一起组装时，反应进行得更快。最后，在不同的相对湿度水平以及不同浓度的氨、乙醇和丙酮中，评估通过LbL在金叉指微电极顶部制备的ST/还原氧化石墨烯（RGO）和PDAC/RGO传感器的气敏性能。与PDAC/RGO传感器相比，含ST的传感器灵敏度更高，尤其是在高相对湿度环境下工作时。由这些化学传感器组成的阵列可为每种被研究的分析物提供独特的电指纹，并能够在10至1000 ppm的广泛浓度范围内对其进行鉴别和定量。
