Carbon Paste Composite with Co3O4 as a New Electrochemical Sensor for the Detection of Allura Red by Reduction

Johisner Penagos-Llanos, Olimpo García-Beltrán, J. A. Calderón, Edgar Nagles, J. J. Hurtado

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The detection of Allura red (AR) by electrochemical reduction using a different electrode from the conventional mercury electrode is presented. A carbon paste with cobalt (II, III) oxide composite electrode (CoOx/CPE) is reported for the first time for the detection of AR. Moreover, others dyes such as tartrazine (TZ), sunset yellow (SY), amaranth (AM), Ponceaut 4-R (P-4R), and Sudan (SD) as well as pharmaceutical agents such as paracetamol (PMC) that are present in samples that contained AR did not show a reduced signal between 0.0 and −0.3 V, which is the potential range where AR reduction was observed. The surface electroactivity was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The presence of CoOX increased the cathodic peak current for AR by more than 50 % and 65 % via CV and square wave voltammetry (SWV), respectively, compared with an unmodified carbon paste electrode. Under the optimal parameters, (pH=3.0, accumulation time (tACC)=60 s and accumulation potential (EACC)=0.50 V), the detection limit for AR was 0.05 μmol L−1. The new sensor was sensitive and stable for the detection of AR. Moreover, it was easily manufactured and very convenient for food samples such as soft and isotonic drinks as well as chili sauce.

Original languageEnglish
Pages (from-to)695-703
Number of pages9
Issue number4
StatePublished - Apr 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Allura red
  • Carbon paste
  • Cobalt (II, III) oxide.
  • Modified electrodes


Dive into the research topics of 'Carbon Paste Composite with Co3O4 as a New Electrochemical Sensor for the Detection of Allura Red by Reduction'. Together they form a unique fingerprint.

Cite this