Nitrite‐Enhanced Charge Transfer to and from Single Polyaniline Nanotubes

Abstract

As Liu et al. reported previously (Appl. Mater. Today 2017, 7, 239-245), the charge transfer to partially oxidized polyaniline (PANI) nanotubes in electrochemical reactions is heavily limited due to the non-conductivity of the reduction/oxidation products. In this paper, the doping level of individual PANI nanotubes was substantially enhanced using nitrite as an electron acceptor in sulfuric acid aqueous solution as recorded by the nano-impact method. The charge transferred to one single tube during reduction process is close to the theoretical value of 170±112 pC per tube (assuming 2-electron reduction for the PANI tubes studied), while the charge during PANI oxidation is dramatically decreased. Reaction processes are proposed based on the oxidative properties of nitrite in acid solution. UV-visible spectroscopy analysis further confirms an oxidation-reduction reaction between PANI and nitrite. In contrast the electrochemical reaction of ensembles (21 μg cm ) of PANI tubes on glassy carbon electrodes simply show limited electrocatalytic activity.

Single Entity Electrochemistry and Its Application to Nanomaterial Synthesis

“…Subsequent studies were published that electrochemically detect single entities of various small dielectrics such as silica nanoparticles, polystyrene, and polymers in a similar way. [6,7]…”

“…[3][4] This electrochemical analysis method continued to develop, using UME to detect dielectric nanoparticles such as silica that collide with the electrode. [5][6][7] In addition, the collision of platinum, gold, and metal oxide nanoparticles was observed by applying catalytic amplification on the surface of the nanoparticles, [8][9][10][11][12][13] and recently, studies have been conducted to observe emulsion droplets colliding with the electrode. [14][15][16][17][18][19] The electrochemical analysis of such soft nanomaterials can be applied not only to emulsion but also to the observation of viruses, DNA, and other biomolecules with considerable accuracy and efficiency compared to previous reported analytical methods.…”

“…Single entity electrochemistry has been accelerated since 1995 with the observation of single molecule electrochemistry in a confined aqueous space surrounded by wax insulator and nanoelectrodes [3–4] . This electrochemical analysis method continued to develop, using UME to detect dielectric nanoparticles such as silica that collide with the electrode [5–7] . In addition, the collision of platinum, gold, and metal oxide nanoparticles was observed by applying catalytic amplification on the surface of the nanoparticles, [8–13] and recently, studies have been conducted to observe emulsion droplets colliding with the electrode [14–19] .…”

The construction of a simple sensor for the simultaneous detection of nitrite and thiosulfate by heme catalysis

“…So how to detect the mixture of NO 2 À and S 2 O 3 2À accurately and sensitively has a certain signicance for food safety and human health. 10,11 Numerous analytical techniques are used for the detection of NO 2 À and S 2 O 3 2À with good sensitivity. Some of the common hyphenated techniques include gas chromatography-mass spectrometry (GC-MS), 12,13 liquid chromatography-mass spectrometry (LC-MS), 14,15 HPLC, 16 uorescence detection, 17 and electrochemical methods.…”

A Facile Electrochemical Sensor Labeled by Ferrocenoyl Cysteine Conjugate for the Detection of Nitrite in Pickle Juice

“…It is also a big world problem that nitrite contamination of drinking water in reservoirs and aquifers directly influence human health, which are contributed by agricultural fertilizers and manure. Consequently, accurate quantitative analysis and effective removal of nitrite is of great importance for human health and environmental protection [4,5].…”