Array of Miniaturized Amperometric Gas Sensors Using Atomic Gold Decorated Pt/PANI Electrodes in Room Temperature Ionic Liquid Films

Abstract

Miniaturized sensors possess many advantages, such as rapid response, easy chip integration, a possible lower concentration of target compound detection, etc. However, a major issue reported is a low signal response. In this study, a catalyst, the atomic gold clusters of Aun where n = 2, was decorated at a platinum/polyaniline (Pt/PANI) working electrode to enhance the sensitivity of butanol isomers gas measurement. Isomer quantification is challenging because this compound has the same chemical formula and molar mass. Furthermore, to create a tiny sensor, a microliter of room-temperature ionic liquid was used as an electrolyte. The combination of the Au2 clusters decorated Pt/PANI and room temperature ionic liquid with several fixed electrochemical potentials was explored to obtain a high solubility of each analyte. According to the results, the presence of Au2 clusters increased the current density due to electrocatalytic activity compared to the electrode without Au2 clusters. In addition, the Au2 clusters on the modified electrode had a more linear concentration dependency trend than the modified electrode without atomic gold clusters. Finally, the separation among butanol isomers was enhanced using different combination of room-temperature ionic liquids and fixed potentials.

Room Temperature NH3 Selective Gas Sensors Based on Double-Shell Hierarchical SnO2@polyaniline Composites

“…When the sensor was exposed to NH 3 , NH 3 captures H + from the -NH- groups, leading to a reduction in the polaron density along the main chain of polyaniline, rendering the PANI in a highly resistive state. The opposite process would occur when the sensor was placed back in air [ 16 ]. …”

“…PANI-sensor-enhanced NH 3 -sensing performance primarily involves strategies such as the formation of p-n heterojunctions by combining PANI with an n-type metal oxide semiconductor (MOS) [ 12 , 13 ], the construction of hollow structures [ 14 , 15 ] and hierarchical structure gas-sensitive materials [ 16 , 17 ]. That is to say, the modulation of surface morphology is particularly essential to enhance the gas-sensitive performance of PANI, which mainly concerns the property enhancement brought by a large specific surface area, multiple active sites and a high porosity with microstructural advantages.…”

New Trend of Amperometric Gas Sensors Using Atomic Gold-Decorated Platinum/Polyaniline Composites

“…Secondly, it is widely reported that RTIL has a wider EC potential window than liquid electrolytes which allows for detecting more target gasses where the redox reaction takes place at a high EC potential. Lastly, using RTIL, a thin film for a miniaturized AGS can be realized and the fluidity issue can be removed due to its high viscosity [27]. In this section, we also provide brief information regarding the structure and several physical-chemical properties of RTIL.…”

“…However, a low sensor signal is the main issue; hence, the atomic catalyst is indeed required to enhance the sensitivity. In the miniaturized AGS, Room Temperature Ionic Liquid (RTIL) was used as a substitute for the aqueous electrolyte due to fluidity and evaporation issues [27]. Although there are many works related to RTILs used for miniaturized AGSs [28,29], using atomic gold with the RTIL is still very new and can be explored.…”

“…Each experiment had 5 min for target gas exposure and 10 min for recovery (N2 flow). Reproduced from[27].…”