Exploring Multiwalled Carbon Nanotubes for Naproxen Detection

Abstract

The electrochemical oxidation of naproxen was investigated at a multiwalled carbon nanotube (MWCNT)‐modified electrode. A decrease (200 mV) in the overpotential of the naproxen oxidation reaction and considerable (4‐fold) current increase (compared to the bare glassy‐carbon electrode) was observed. Two one‐electron transfers were verified at both bare and MWCNT‐modified electrodes and thus a new mechanism for the electrochemical oxidation of naproxen is proposed. Indicative of a mass transport regime that includes a thin‐layer diffusional process (entrapment of naproxen species within the MWCNT film) is presented as a possible explanation for the lowered oxidation potential and substantial current increase. The anti‐fouling properties of MWCNTs on the amperometric detection of naproxen using a batch‐injection analysis (BIA) system is demonstrated.

Multi-walled carbon nanotubes: Size-dependent electrochemistry of phenolic compounds

“…The plots of current of HQ, TBHQ, CT, and DP at the GCE, LD-MWCNT, and SD-MWCNT surfaces in function of the square root of scan rate (in the range of 10 and 1000 mV s À1 ) were highly linear (R > 0.99) and crossed the origin, which indicates that all electrochemical processes were diffusion- controlled (plots not shown). Therefore, no adsorption effects can be inferred in the electrochemical oxidation of the four analytes either of the both MWCNT-modified GCE surfaces considering the conditions of MWCNT-film formation in this work [10][11][12][13]. Fig.…”

“…However, metallic impurities in CNTs can also be responsible for their claimed electrocatalytic properties [8,9]. Another possible explanation for the lowered reduction or oxidation potentials observed in CNTmodified electrodes is the alteration of the mass transport regime from linear (planar) diffusion to thin layer diffusion as the CNTmodified electrode can be considered as a conducting porous layer [10][11][12][13]. Similar behaviour was reported for electrochemical processes on metal-hexacyanoferrate films [14], and evidences of the entrapment of electroactive species within the film were obtained by electrochemical surface plasmon resonance and electrochemical quartz crystal microbalance [15].…”

Size effects of multi-walled carbon nanotubes on the electrochemical oxidation of propionic acid derivative drugs: Ibuprofen and naproxen

“…4 B). semi-infinite diffusion regime [43][44][45], which was reported in a previous report using the LD-MWCNT-modified GCE for NPX detection [27]. As stated in previous works hand, NPX presents a methoxy-naphthyl ring, which is highly aromatic in nature, that may interact strongly with the sidewalls of MWCNT structure through π -π bonds [48,49], which did not occur with the IBF molecule.…”

“…Decrease in the overpotential of electrochemical oxidation reactions, increase in the electrode active surface area, and anti-fouling properties of electrodes are the main advantages reached after electrode modification with CNTs [31]. These properties were obtained for NPX detection reported in previous studies using CNTs [27][28][29]. However, to the best of our knowledge, there are no reports on the use of CNTs for the electrochemical sensing of IBF.…”

“…The electrochemical oxidation of IBF was investigated at a boron-doped diamond electrode (BDDE) after anodic treatment and its oxidation occurred at around +1.7 V vs. Ag/AgCl (saturated KCl) using square-wave voltammetry [21] and amperometric detection in a flow-injection analysis (FIA) system [22]. NPX was detected on unmodified platinum [23], BDDE [24], glassy-carbon A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 4 electrodes [25], and on modified electrodes with dysprosium nanowires [26], carbon nanotubes (CNTs) [27,28] and the composite ZnO attached to CNTs [29].…”