Application of Polyvinylpyrrolidone-Stabilized Silver Nanoclusters as Fluorescent Probes for Trace Iodide in Seaweed

Why It Matters

Accurate, inexpensive iodide monitoring supports public health nutrition goals and reduces reliance on expensive laboratory equipment.

Key Takeaways

• AgNCs@PVP probe detects iodide down to 56 nM.
• Linear response spans 0.29–280 µM covering typical seaweed levels.
• Recovery 92–106% and RSD < 3% in real seaweed samples.
• Probe shows high selectivity; common ions do not interfere.
• Synthesis uses inexpensive PVP, enabling low‑cost, scalable production.

Pulse Analysis

Iodine deficiency and excess both pose serious health risks, making precise measurement of trace iodide in foods a regulatory priority. Traditional techniques such as ICP‑MS deliver ultra‑low detection limits but demand costly instrumentation, extensive sample preparation, and skilled operators. Fluorescent sensing, by contrast, can deliver comparable sensitivity with simpler workflows, positioning nanomaterial‑based probes as attractive tools for routine food‑safety labs and even field testing scenarios.

Silver nanoclusters stabilized by polyvinylpyrrolidone combine strong, photostable emission with biocompatibility, while PVP’s polymeric matrix prevents aggregation and enhances water solubility. The AgNCs@PVP probe leverages an inner‑filter effect—iodide absorbs in the excitation band—and a static quenching interaction to achieve a 56 nM detection limit, surpassing many organic dyes and rivaling the performance of high‑end spectrometric methods. Selectivity tests confirm that common seaweed constituents (Na⁺, K⁺, Ca²⁺, etc.) do not interfere, and the probe maintains consistent fluorescence across a broad pH range, simplifying sample handling.

Beyond seaweed, the platform’s low material cost and straightforward synthesis open pathways for broader deployment in seafood, dairy, and water monitoring. Its rapid response (minutes) and minimal equipment needs could democratize iodide testing, especially in resource‑limited settings. Future work may integrate the probe into portable handheld fluorometers or microfluidic chips, expanding its utility for on‑site nutritional assessments and supporting public‑health initiatives aimed at balancing iodine intake worldwide.