Novel ratiometric electrochemical sensing platform with dual-functional poly-dopamine and NiS@HCS signal amplification for sunset yellow detection in foods

• Published in: Food chemistry 2022-10, Vol.390, p.133193-133193, Article 133193
• Main Authors: Chen, Yongfeng, Waterhouse, Geoffrey I.N., Sun, Hemei, Qiao, Xuguang, Sun, Yufeng, Xu, Zhixiang
• Format: Article
• Language: English
• Subjects: Hollow carbon spheres; Nickel sulfide; Poly-dopamine; Ratiometric electrochemical sensor; Sunset yellow
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.133193

•A signal on/off ratiometric PDA/NiS@HCS/GCE sensor was developed for sunset yellow.•Poly-dopamine was used as an internal reference probe and for signal amplification.•Highly conductive NiS@HCS aided SY quantification over a wide linear range.•The developed sensor exhibited excellent practical utility for SY detection in food. In this work, a novel ratiometric electrochemical sensor based on dual-functional poly-dopamine (PDA) and nickel sulfide@hollow carbon spheres (NiS@HCS) was successfully developed for sunset yellow (SY) detection. The NiS@HCS nanocomposite possessing a large specific surface area, good catalytic activity and excellent electrical conductivity was employed for signal amplification. PDA films prepared by electropolymerization acted as an internal reference probe and enhanced the sensitivity of the proposed sensor through electrostatic attraction between SY and PDA. Under optimized conditions, the developed PDA/NiS@HCS/GCE sensor allowed SY quantification over wide linear range (0.01–100 μM), with a low limit of detection of 0.003 μM. SY recovery tests were carried out in rice vinegar and cooking wine with satisfactory recoveries (83.50–112.80 %). Meanwhile, the content of SY in two kinds of carbonated drinks was determined using the constructed sensor and a UV–Vis spectrometry method, with no significant difference found in the results.