An ammonia-sensitive fluorescence sensor based on polyvinyl alcohol-graphene quantum dots/halloysite nanotubes hybrid film for monitoring fish freshness

• Published in: Food chemistry 2024-10, Vol.454, p.139734, Article 139734
• Main Authors: Zhang, Jiaran, Yu, Jie, Yin, Hao, Jia, Zhixin, Shi, Ce, Yue, Yuntao
• Format: Article
• Language: English
• Subjects: ammonia; Ammonia - analysis; Ammonia - chemistry; Animals; Clay - chemistry; Fishes; Fluorescence; Fluorescence film; Food Contamination - analysis; Food Packaging - instrumentation; Freshness; Graphene quantum dots; Graphite - chemistry; Halloysite nanotubes; Limit of Detection; Nanotubes - chemistry; Polyvinyl Alcohol - chemistry; Quantum Dots - chemistry; Seafood - analysis; Spectrometry, Fluorescence
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139734

A fluorescent hybrid film composed of nitrogen-doped graphene quantum dots (N-GQDs) loaded on halloysite nanotubes (HNTs) (N-GQDs/HNTs nanocomposite) as a sensitive element and polyvinyl alcohol (PVA) as a film-forming matrix was designed for freshness detection. The PVA-N-GQDs/HNTs hybrid film exhibited significantly enhanced fluorescence attributed to the loading of N-GQDs onto the surface of HNTs through electrostatic interactions and hydrogen bonding, effectively reducing their aggregation. The fluorescence of the hybrid film could be quenched by ammonia via photoinduced electron transfer (PET), with good linearity in the range of 20 ppm to 500 ppm ammonia and a limit of detection (LOD) of 0.63 ppm. In addition, the hybrid film was applied to monitor the freshness of seawater fish and freshwater fish stored at refrigeration and room temperature to evaluate the practicality of this approach. The developed hybrid film showed promise for nondestructive and on-site monitoring of fish spoilage. •An ammonia-sensitive sensor based on PVA-N-GQDs/HNTs hybrid film was constructed.•N-GQDs were loaded on HNTs via electrostatic interactions and hydrogen bonding.•The anchoring and diluting effect of HNTs on N-GQDs enhanced the fluorescence.•The detection mechanism was based on the photoinduced electron transfer effect.•Good selectively detection of fish freshness at different temperature were achieved.