Interference of Ascorbic Acid in the Sensitive Detection of Dopamine by a Nonoxidative Sensing Approach

Abstract

The electrochemistry of a poly(anilineboronic acid)/carbon nanotube composite was studied in the presence of dopamine and ascorbic acid. To understand the binding affinity of dopamine and ascorbic acid to the boronic acid functional groups in the composite, the association constants between the diol groups in dopamine and ascorbic acid and the boronic acid were experimentally determined using a fluorescence-based binding assay. The results demonstrate that ascorbic acid could severely interfere with the detection of dopamine in nonoxidative boronic acid-binding approaches: Ascorbic acid was able to electrocatalytically reduce the fully oxidized polyaniline backbone during the electrochemical oxidation process; similarly to dopamine, ascorbic acid was also able to bind to the boronic acid groups through its planar diol group even though the binding affinity is much lower. The examination of the dopamine transduction mechanism and ascorbic acid interference mechanism in this nonoxidative approach will benefit the design of future boronic acid-based sensors.

L-cysteine capped ZnS:Mn quantum dots for room-temperature detection of dopamine with high sensitivity and selectivity

“…$ 1.6-fold less intense than the intensity drop produced by AA, the most competitive interferent in the determination of DA. AA is found in excess (compared to DA) in the extracellular fluid of the central nervous system, where both co-exist (Ali et al, 2007). The fact that AA does not affect significantly the phosphorescence intensity of the probe is likely due to its low binding constant with L-cysteine (Ankireddy et al, 2015;Ban et al, 2015), and this result can be used to determine DA concentrations without further sample separation.…”

Polyaniline-carbon nanotube composites

“…Another sensor for NADH has been developed with poly(1,2-diaminobenzene)-MWCNT composite in a range from 2 µM to 4 mM [150]. A CNT composite of poly(anilineboronic acid) functionalized with single-strand DNA (ss-DNA) shows great promise for the effective detection of dopamine of concentration as low as 40 pM without any interference from ascorbic acid [77,151,152]. Similarly, a PANI-β-cyclodextrin-MWCNT composite can be used for the selective detection of dopamine up to 1.2 × 10 -8 M in the presence of ascorbic acid [153].…”

Graphene Oxide‐Templated Polyaniline Microsheets toward Simultaneous Electrochemical Determination of AA/DA/UA

“…However, PAN was reported to be insensitive to DA. This situation could be improved by introducing suitable functional groups into the polymer backbone [19] or incorporating PAN with other materials which are sensitive to DA, such as gold nanoparticles [20], carbon nanotubes [21,22], etc. Another route [23] to enhance the selectivity is to overoxidize poly(N-acetylaniline) to exclude the negative ascorbic ions from the electrode while accumulate the positive DA ions due to the charged characters of DA and AA.…”