Open AccessSensitive Electrochemical Sensor Based On an Aminated MIL-101(Cr) MOF for the Detection of Tartrazine
Author(s) -
Raïssa Tagueu Massah,
Sherman Lesly Zambou Jiokeng,
Jun Liang,
Evangéline Njanja,
Tobie J. Matemb Ma Ntep,
Alex Spieß,
Lars Rademacher,
Christoph Janiak,
Ignas Kenfack Tonlé
Publication year - 2022
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.2c01106
Subject(s) - tartrazine , electrochemical gas sensor , electrochemistry , chemistry , computer science , chromatography , electrode
The aminated metal-organic framework H 2 N-MIL-101(Cr) was used as the carbon paste electrode (CPE) modifier for the determination of tartrazine (Tz) in soft drinks. The amino material was characterized by electrochemical impedance spectroscopy and showed significantly faster electron transfer with lower charge-transfer resistance (0.13 kΩ) compared to the electrode modified with the unfunctionalized MIL-101(Cr) material (1.1 kΩ). The H 2 N-MIL-101(Cr)-modified CPE [H 2 N-MIL-101(Cr)-CPE] was then characterized by cyclic voltammetry (CV) using [Fe(CN) 6 ] 3- and [Ru(NH 3 ) 6 ] 3+ ions as the redox probes, showing good accumulation of [Fe(CN) 6 ] 3- ions on the electrode surface. A CV scan of Tz in Britton Robinson buffer solution revealed an irreversible system with an oxidation peak at +0.998 V versus Ag/AgCl/KCl. Using CV and differential pulse voltammetry, an electrochemical method for quantifying Tz in aqueous medium was then developed. Several parameters that affect the accumulation and detection steps were optimized. Optimal detection of Tz was achieved after 180 s of accumulation in Britton Robinson buffer solution (pH 2) using 2 mg of H 2 N-MIL-101(Cr) material. Under optimal conditions, the sensor exhibited a linear response in the concentration range of 0.004-0.1 μM and good detection sensitivity (35.4 μA μM -1 ), and the detection limit for Tz was found to be 1.77 nM (S/N = 3). Satisfactory repeatability, stability, and anti-interference performance were also achieved on H 2 N-MIL-101(Cr)-CPE. The sensor was applied to commercial juices, and the results obtained were approximately similar to those given by UV-vis spectrophotometry.