Design and Development of Amperometric Gas Sensor With Atomic Au–Polyaniline/Pt Composite

Abstract

Rapid advancements in information processing and embedded systems require high selective and fast sensors. Conventional gas sensors are not suitable for the detection of isomers of organic compounds due to cross-sensitivity and the response time being limited by slow chemical kinetics. Amperometric gas sensors using conducting polymers modified with metal catalysts are a suitable and robust system due to many tunable properties. In this paper, conducting polymer polyaniline was electrochemically decorated with clusters containing precisely defined number of gold atoms to function as an electro-catalyst. The modified polymer composite showed fast reaction rate for the electro-oxidation of alcohols in both liquid and gas phases. The number of gold atoms affected the catalytic activity. Cyclic voltammograms were measured and results showed discriminable patterns between n-propanol and isopropanol even at different gas concentrations. Thus, it was demonstrated that gas sensor arrays can be realized by decorating different number of gold atoms on polyaniline electrodes, to yield defined and different selectivity. Index Terms-Amperometric gas sensor, atomic gold, conducting polymer, electro-catalyst, polyaniline, propanol I. INTRODUCTIONGas sensors have a wide range of modern applications such as their use in breath analysis to detect anomaly in a patient's health, as security devices for monitoring gas leaks, quality control in the food industry etc. [1]. Conventional gas sensors, however, are known to face some common challenges such as cross-sensitivity to humidity [2] and amperometric gas sensors are electrochemical type of gas sensors that are a more robust choice due to their several merits [3] in terms of characteristics such as low power, ease of fabrication, and the ability to perform in humid conditions. Although such sensor characteristics are attractive, they come at a cost of slow

Indirect Sensing of Lower Aliphatic Ester Using Atomic Gold Decorated Polyaniline Electrode

“… Odd–even pattern in the peak current density due to the HOMO-LUMO energy gap energy variation of atomic size clusters [ 10 , 11 , 12 , 13 , 15 ]; figure shows the electrooxidation of 0.5 M n-propanol in 1 M KOH (scan rate = 100 mV/s). …”

“…In this research, PANI electrodes have been decorated with bi-atomic gold and the thus-fabricated nanocomposites have been used as sensing material for the classification between normal-propanol (n-propanol) and iso-propanol (i-propanol). The enhanced sensitivity and selectivity obtained due to the electrocatalytic activity of atomic gold are harnessed as useful properties for sensing in both liquid and gas phases [ 13 , 15 , 16 ]. Although cyclic voltammetry shows that atomic Au-PANI nanocomposites can be used as sensing material for alcohols, fundamental study needs to be conducted with other functional groups as well.…”

Developments of the Electroactive Materials for Non-Enzymatic Glucose Sensing and Their Mechanisms

“…It is further presented that the current response of the electro-oxidation of the 2-propanol (C 3 H 7 OH) altered with the different configurations of the atomic Au-Pd clusters [266,267]. The discrimination between the alcohol series, such as methanol, ethanol, propanol, and butanol, has also been reported [269][270][271][272]. Although the articles were concerned with the electro-oxidation of the alcohol series in the alkaline solution, the reaction mechanisms are very similar to those of the electro-oxidation of glucose and the interfering molecules, such as ascorbic acid (AA), uric acid (UA), dopamine (DA), fructose, and so on.…”

“…Therefore, it is considered that the atomic bi-metallic catalysts deposited supporting material of PANI could be a promising material for the electro-oxidation of glucose in the alkaline solution. In addition, according to the literature [266][267][268][269][270][271][272], the isomers of the propanol, such as 1-propanol and 2-propanol, could also be recognized by the atomic metal and/or alloy electrodes. It is thus deduced that the isomers of the glucose, such as the α-D-glucose and the β-D-glucose are also expected to be recognized by the atomic metal and/or alloy electrodes.…”

“…According to the aforementioned results, it is highly possible to enhance the electrocatalytic activity, promote the anti-poisoning effect, and improve the selectivity of the electrode materials for the electro-oxidation of glucose by combining the atomic deposition of alloy systems via the flow cell system [266][267][268][269][270][271][272]. In addition, a great variety of the metals, similar to those in Table 4, is considered to be realized by simply altering the compounds of the metal salts in the electrolyte, such as KAuCl 4 , K 2 PdCl 4 , K 2 PtCl 4 , K 2 CoCl 4 , and KNiCl 4 .…”