A Colorimetric Sensor for the Visual Detection of Azodicarbonamide in Flour Based on Azodicarbonamide-Induced Anti-Aggregation of Gold Nanoparticles

Abstract

Azodicarbonamide (ADA) in flour products can be converted into carcinogenic biurea and semicarbazide hydrochloride after baking. Thus, it is mandatory to determine ADA in flour. We herein developed a colorimetric method for the rapid and visual detection of ADA in flour based on glutathione (GSH)-induced gold nanoparticles (AuNPs) aggregation and specific reaction between ADA and GSH. The GSH can react to AuNPs via Au-SH covalent bond to form a network structure, which leads to AuNPs aggregation to produce color change, whereas ADA can specifically react with GSH to lead to the coupling of two GSH molecules, which makes GSH lose a −SH group and thus decreases the aggregation degree of AuNPs induced by GSH. This provided a platform for field-portable colorimetric detection of ADA. The colorimetric sensor can be used to detect as little as 0.33 μM (38.3 ppb) of ADA by naked eye observation and 0.23 μM (26.7 ppb) of ADA by spectrophotometry within 2 h. The method was successfully used to detect ADA in flour with a recovery of 91–104% and a relative standard deviation (RSD) < 6%. The visual detection limit of sensor is lower than the ADA limitation in flour (45 mg/kg), which makes the sensor a potential approach for the instrument-free visual and on-site detection of ADA in flour.

Noble Metal Nanoparticles Applications: Recent Trends in Food Control

“…This method can be used for a rapid sensing of acrylamide traces in food, with a 0.2 nM limit of detection and a lower relative error (RSD%) compared to the accepted HPLC method [41]. Also, for azodicarbonamide (ADA) in flour products, a colorimetric method has been developed [42], based on glutathione (GSH)-induced gold nanoparticle (AuNPs) aggregation. This method, with high recoveries (91–104%) and low RSD% (<6%), can be used to detect 38.3 ppb of ADA by naked eye observation and 26.7 ppb of ADA by spectrophotometry, both lower than the ADA limitation in flour (45 mg/kg).…”

A novel imidazole‐derived Schiff base as selective and sensitive colorimetric chemosensor for fluorescent detection of Cu2+ in methanol with mixed aqueous medium

“…The colorimetric sensors have displayed great potential for the detection of metallic ions, anions, organic dyes, drugs, and other toxic pollutants due to their easy preparation, quick detection, high sensitivity, and naked-eye sensing. [25,26] In addition, fluorescence chemosensors have attracted great consideration because of their easy operation, high sensitivity, low cost, and miniaturization. The spectrofluorimetry technique is an alternate to these methods, which have concerned great interests for their highly simplicity, selectivity, sensitivity, and quick response.…”

Rapid and selective detection of aluminum ion using 1,2,3-triazole-4,5-dicarboxylic acid-functionalized gold nanoparticle-based colorimetric sensor

“…Taking advantages of unique surface plasmon resonance (SPR) absorption, easy surface functionalization and variable solution colors, AuNPs have been used for colorimetric sensing in food security, environmental monitoring, and health care. [8][9][10][11] Potential applications include the determination of metal ions, [12][13][14][15][16][17][18] pesticide residues, 19,20 bisphenol A (BPA), 21,22 phosphate, 23 azodicarbonamide (ADA), 24 antibiotics, [25][26][27] adenosine and nucleic acids, [28][29][30] dopamine, 31 bacteria, 32,33 and virus. 34,35 In recent years, rapid detection of Al 3+ using AuNPs as a colorimetric sensor have been reported, in which the AuNPs' surface were functionalized by different Al 3+ recognition ligands, such as diaminodiphenyl sulfone, 36 ascorbic acid, 37 11mercaptoundecanoic acid, 38 5-mercaptomethyltetrazole, 39 poly(acrylic acid), 40 triazole ether, 41 catechol, 42 and xylenol orange.…”

“…Taking advantages of unique surface plasmon resonance (SPR) absorption, easy surface functionalization and variable solution colors, AuNPs have been used for colorimetric sensing in food security, environmental monitoring, and health care. 8–11 Potential applications include the determination of metal ions, 12–18 pesticide residues, 19,20 bisphenol A (BPA), 21,22 phosphate, 23 azodicarbonamide (ADA), 24 antibiotics, 25–27 adenosine and nucleic acids, 28–30 dopamine, 31 bacteria, 32,33 and virus. 34,35 …”