This work reported the rapid in situ detection of ultratrace 2,4-dinitrotoluene (DNT) solids on various substrates by a sandwiched paper-like electrochemical sensor. The sensor, prepared by a simple electroless deposition method without using special instruments, possessed a unique thin-film structure of an insulated polyvinylidene fluoride (PVDF) membrane in between two gold (Au) conducting layers. The resulting gold–PVDF sandwich (GPVDFS) array exhibited excellent flexibility, porosity and electrochemical performance as a highly integrated dual-electrode sensor platform. The infiltration of nonvolatile ionic liquid (IL) electrolytes containing ferrocene (Fc) into the GPVDFS array produced a paper-like electrochemical sensor, which can directly detect ultratrace DNT solids on various substrate surfaces (e.g., plant leaves, gloves and metal knives) with detection limit as low as 0.33 ng/mm². The critical role of Fc in the detection of DNT at this dual-electrode sensor was explored. The compensating electrochemical oxidation of Fc at the counter/reference electrode was found to be essential to the reduction of DNT at the working electrode when IL electrolytes were employed. The present work thus demonstrated the promising applications of paper-based porous electrode arrays in developing IL-based electrochemical sensors for the in situ detection of analyte solids in complicated environments.

中文翻译：

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夹心纸状电化学传感器快速原位检测超痕量的2,4-二硝基甲苯固体

这项工作报道了通过夹纸样电化学传感器在各种基材上快速原位检测超痕量的2,4-二硝基甲苯（DNT）固体。该传感器采用简单的化学沉积方法，无需使用特殊仪器即可制备，在两个金（Au）导电层之间具有绝缘的聚偏二氟乙烯（PVDF）膜的独特薄膜结构。作为高度集成的双电极传感器平台，所得的金-PVDF三明治结构（GPVDFS）具有出色的柔韧性，孔隙率和电化学性能。含二茂铁（Fc）的非易失性离子液体（IL）电解质渗透到GPVDFS阵列中产生了一种纸状电化学传感器，该传感器可以直接检测各种底物表面（例如植物叶片，²。探索了Fc在此双电极传感器中检测DNT的关键作用。发现当使用IL电解质时，对/参比电极上的Fc的补偿电化学氧化对于减少工作电极上的DNT是必不可少的。因此，本工作证明了纸基多孔电极阵列在开发用于复杂环境中原位检测分析物固体的基于IL的电化学传感器方面的有希望的应用。