Aggregation-induced emission and absorption enhancement of mixed-valent rhenium oxide quantum dots by triethylamine: Implications for food safety monitoring

Manivannan Madhu; Aravindan Varatharajan; S Santhoshkumar; Wei-Bin Tseng; Po-Chiao Lin; Wei-Lung Tseng

doi:10.1016/j.jhazmat.2024.137049

Aggregation-induced emission and absorption enhancement of mixed-valent rhenium oxide quantum dots by triethylamine: Implications for food safety monitoring

J Hazard Mater. 2024 Dec 31:486:137049. doi: 10.1016/j.jhazmat.2024.137049. Online ahead of print.

Authors

Manivannan Madhu¹, Aravindan Varatharajan², S Santhoshkumar², Wei-Bin Tseng³, Po-Chiao Lin², Wei-Lung Tseng⁴

Affiliations

¹ Department of Chemistry, National Sun Yat-sen University, No. 70 Lienhai Rd., Kaohsiung 80424, Taiwan; Center for Global Health Research, Saveetha Medical college and Hospital, Saveetha Institute of Medical and Technical Sciences, Thandalam, Chennai 602 105, India.
² Department of Chemistry, National Sun Yat-sen University, No. 70 Lienhai Rd., Kaohsiung 80424, Taiwan.
³ Department of Chemistry, National Sun Yat-sen University, No. 70 Lienhai Rd., Kaohsiung 80424, Taiwan; Department of Environmental Engineering, Da-Yeh University, No.168, University Road, Dacun, Changhua 515006, Taiwan.
⁴ Department of Chemistry, National Sun Yat-sen University, No. 70 Lienhai Rd., Kaohsiung 80424, Taiwan; Center for Nanoscience & Nanotechnology, National Sun Yat-sen University, No. 70 Lienhai Rd., Kaohsiung 80424, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, No.100, Shiquan 1st Rd., Kaohsiung 80708, Taiwan. Electronic address: tsengwl@mail.nsysu.edu.tw.

PMID: 39754875
DOI: 10.1016/j.jhazmat.2024.137049

Abstract

Food freshness monitoring and volatile amine detection are key to food safety. In this study, we demonstrated the applicability of mixed-valence rhenium oxide quantum dots (MV-ReOQDs), synthesized via the hydrothermal reaction of α-cyclodextrin and rhenium ion precursors, in triethylamine (TEA) sensing. Spectroscopic correlation techniques showed that the developed MV-ReOQDs possessed mixed-valent rhenium, α-cyclodextrin as capped ligand, partially carbonized surface, and amorphous phase structure. The multiple oxidation states in the MV-ReOQDs facilitated electron precipitation, contributing to increased excitation-dependent emission, broadened absorption band, and extended luminescence lifetime with increasing emission wavelength. TEA was found to trigger aggregation-induced emission enhancement (AIEE) in the MV-ReOQDs owing to hydrophobic inclusions and hydrogen bonding. Moreover, TEA engaged in charge-transfer interactions with the MV-ReOQDs, amplifying their visible absorption. The MV-ReOQDs afford a limit of detection (signal-to-noise ratio of 3) for TEA at 5 µM (0.5 ppm) for colorimetric detection and 700 nM (0.071 ppm) in luminescent detection modes. Embedding the MV-ReOQDs onto a filter paper yielded a straightforward tool for the real-time detection of TEA vapors released during shrimp spoilage. This MV-ReOQD-coated filter paper provides a convenient solution for monitoring food freshness and facilitates safer food handling and quality control practices.

Keywords: Aggregation-induced emission enhancement; Food safety; Mixed-valence; Rhenium oxide; Triethylamine.