Hydrogen peroxide (H₂O₂) is widely used as a disinfectant and oxidizing agent in food processing, pharmaceuticals, and consumer products, but excessive residues can degrade nutrients, damage tissues, and increase health risks. Conventional detection methods often require specialized equipment or suffer from background autofluorescence. A new study introduces a persistent luminescence nanoparticle (PLNP)-based optical probe that overcomes these limitations, enabling rapid, sensitive, and on-site H₂O₂ monitoring.
Researchers at Chengdu University and Hefei University of Technology developed the nanoprobe, PLNPs@MnO₂, by coating near-infrared ZnGa₂O₄:Cr persistent luminescence nanoparticles with a manganese dioxide (MnO₂) shell. In its initial state, the MnO₂ layer quenches the luminescence via interfacial electron transfer, producing a "turned-off" signal. When H₂O₂ is present in a mildly acidic environment, MnO₂ is reduced to Mn²⁺, restoring the persistent luminescence and generating a bright red signal proportional to H₂O₂ concentration. The detection limit reaches 0.079 μmol/L, more sensitive than many conventional sensors. The findings were published on August 28, 2025, in Food Quality and Safety (DOI: 10.1093/fqsafe/fyaf040).
The probe's restored red luminescence can be visually recognized under UV illumination, allowing detection on flat plates or paper substrates without instruments. It demonstrates strong anti-interference performance against common ions, sugars, amino acids, and proteins, with excellent reproducibility and batch stability. Applications in bottled water, milk, and contact lens solutions yielded recovery rates from 90.56% to 109.73%, confirming reliability in real samples.
"The key innovation is overcoming autofluorescence interference, which has long limited optical sensing in food and biological matrices," said the study's corresponding author. "By using persistent luminescence, our method produces clean, high-contrast signals without continuous excitation, making it suitable for rapid, portable detection outside laboratories."
This autofluorescence-free strategy offers practical advantages for food safety monitoring, environmental inspection, and biomedical assays. Its naked-eye detection capability is valuable in remote or resource-limited settings. Future development may integrate the probe into smart packaging, wearable chemical sensors, and real-time contamination alert systems. By simplifying H₂O₂ detection, this technology supports safer processing environments and improved product quality assurance.
