Persistent Luminescence Nanoprobe Enables Rapid Hydrogen Peroxide Detection Without Autofluorescence Interference

A new persistent luminescence nanoparticle-based optical probe has been engineered to detect hydrogen peroxide with high sensitivity while eliminating autofluorescence interference, addressing significant limitations in current detection methods. Hydrogen peroxide plays essential roles in industrial processing, food production, and biological systems, but excessive residues pose health and safety concerns including gastrointestinal irritation and potential cancer risk. Conventional detection methods often require specialized equipment, continuous excitation, or complex sample preparation, while background autofluorescence in food or biological samples frequently reduces signal clarity and accuracy.

Researchers at Chengdu University and Hefei University of Technology developed the PLNPs@MnO₂ nanoprobe, where near-infrared ZnGa₂O₄:Cr persistent luminescence nanoparticles are uniformly coated with a manganese dioxide shell to create a switchable optical sensing system. In its initial state, the MnO₂ layer effectively quenches luminescence through interfacial electron transfer, resulting in a turned-off signal. When hydrogen peroxide is present in a mildly acidic environment, MnO₂ rapidly reduces to Mn²⁺, interrupting the quenching pathway and immediately restoring persistent luminescence, producing a clear, intensity-dependent signal. The findings were published in Food Quality and Safety with the study available at https://doi.org/10.1093/fqsafe/fyaf040.

The detection system achieves a remarkably low detection limit of 0.079 μmol/L, significantly more sensitive than many conventional fluorescence or electrochemical sensors that often suffer from background autofluorescence or matrix interference. The restored red luminescence can be visually recognized under UV illumination, allowing detection to be performed directly on flat plates or paper substrates without any instruments. This capability makes the technology particularly valuable in remote or resource-limited settings where laboratory instruments are unavailable. The probe demonstrated strong anti-interference performance in the presence of common ions, sugars, amino acids, and proteins, while exhibiting excellent reproducibility and batch stability.

Applications in real sample environments including bottled water, milk, and contact lens solutions yielded recovery rates ranging from 90.56% to 109.73%, confirming its reliability for practical use. The autofluorescence-free detection strategy offers significant advantages for food safety monitoring, environmental inspection, and biomedical assays by producing clean, high-contrast signals without requiring continuous excitation. This technology represents a versatile platform for rapid, sensitive, and on-site hydrogen peroxide monitoring that could potentially be integrated into smart packaging, wearable chemical sensors, and real-time contamination alert systems to support safer processing environments and improved consumer product quality assurance.