A novel substitution -sensing for hydroquinone and catechol based on a poly(3-aminophenylboronic acid)/MWCNTs modified electrode

Abstract

A facile electrochemical sensor for hydroquinone (HQ) and catechol (CC) determination was successfully fabricated by the modification of poly(3-aminophenylboronic acid) (pAPBA) film and multi-walled carbon nanotubes (MWCNTs) on a glassy carbon electrode (pAPBA/MWCNTs/GCE). The prepared sensor was characterized by scanning electron microscope and electrochemical impedance spectroscopy. Under optimal conditions, differential pulse voltammetry was employed to quantify individual HQ and CC within the concentration range of 5.0 × 10(-7)-4.0 × 10(-5) mol L(-1) and 7.0 × 10(-6)-1.0 × 10(-4) mol L(-1), respectively. Based on the covalent binding between the boronic acid groups of pAPBA film and the cis-diol-containing molecule, a novel substitution-sensing strategy was proposed for the highly sensitive determination of CC. With the addition of CC into HQ solution, covalent interaction between CC and APBA occurred and the HQ was displaced by CC, resulting in a decrease of HQ oxidation peak current and the increase of the CC oxidation peak current. The summation of both current changes (Δ|IHQ| + Δ|ICC|) were combined for CC sensitive detection in a concentration range of 4.0 × 10(-8)-1.7 × 10(-5) mol L(-1) with a limit of detection of 4.3 × 10(-9) mol L(-1). The sensor was successfully applied to the determination of CC in spiked water samples.

A Concentric Ring Electrode for a Wall‐jet Cell in a Microfluidic Device

“…The detection limit (LOD) of catechol was determined to be 6.2 nmol/L (S/N=3), while the LODs of most of electrochemical detectors in a conventional flow‐injection system are on the sub‐μmol/L level . In addition, this LOD for catechol was comparable or superior to those of microfluidic analytical systems with electrochemical detection (Table S1) . The present study confirmed the high sensitivity and good performance of the developed flow cell with the optimized ring array electrode.…”

Cysteamine Capped Silver Nanoparticles and Single‐walled Carbon Nanotubes Composite Coated on Glassy Carbon Electrode for Simultaneous Analysis of Hydroquinone and Catechol

“…The resistance of the charge transfer on the electrode surface (R ct ) is represented as a semicircle diameter in the Nyquist diagram. The bare GCE presented a semicircle (∼251.1 Ω) domain as expected for a very low electron transfer resistance to the redox probe (Figure A).…”

“…Also, E pa shifted to more positive values with the increased in the scan rates, proposing the electron transfer be quasi‐reversible .…”

Metal Organic Framework‐235 (MOF‐235) Modified Carbon Paste Electrode for Catechol Determination in Water

“…It is important to indicate that, to date, electrochemical methods [1, 29–43], have been applied to the detection of catechol. For this reason, a comparison of the proposed method with other electrochemical methods by using modified materials was listed in Table 1.…”