Abstract
Microplastic (MP) contamination in food has become an emerging food safety concern due to its ubiquity and potential health implications. This study presents the development of a novel dual-mode detection platform based on Nile Red-functionalized carbon dots (NR-CDs) for the rapid identification of microplastics in food matrices through fluorescence microscopy and a strip-based visual detection approach. Low-density polyethylene (LDPE) and polypropylene (PP) microplastics (<100 µm) were cryogenically prepared from standard pellets and characterized by FTIR-ATR, showing polymer match scores of 0.935 and 0.912, respectively. Model food samplesmilk, tetra pack milk, bottled juice, and cheesewere spiked with 3 mg of MPs per 30 mL (or 15 g for cheese) and successfully visualized via Nile Red staining under green excitation (525–545 nm), producing strong red fluorescence without background interference. The synthesized NR-CDs exhibited a broad absorption near 280 nm and red photoluminescence under green light excitation, with a mean particle size of ~2–4 nm confirmed by TEM. NR-CDs were incorporated onto filter paper strips, which enabled distinct red fluorescence under fluorescence microscope in the presence of as little as 0.2 mg of MPs in 2 mL water. The developed detection strips provided a simple, rapid, and low-cost method for on-site screening of MPs in food. This work demonstrates, for the first time, the application of NR-CDs for portable, semi-quantitative detection of microplastics, offering a promising tool for real-world food safety monitoring and surveillance.
Presenters
Arvind KumarAssociate Professor, Dairy Science and Food Technology, Banaras Hindu University, Uttar Pradesh, India
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
2026 Special Focus—Living with Water: Food and Life
KEYWORDS
Microplastics, Carbon Dots, Fluorescence Detection, Nile Red, Strip-Based Sensing, Food
