Persistent luminescent nanoparticle-based immunochromatographic assay integrated with a smartphone device for...

Conventional multicolor fluorescent labeling has inconsistent signal and low quantum yield, restricting sensitivity for low-abundance mycotoxin detection. This study developed a dual-channel immunochromatographic assay (ICA) strip based on color-coding properties of persistent luminescent nanoparticles (PLNPs). By precisely controlling the type of doping ions in Zn₂GeO₄ (ZGO) and optimizing the reaction pH, PLNPs with intense green and blue emission were successfully synthesized. The as-prepared PLNPs exhibit high quantum yield and robust optical stability, which effectively reduce background interference from ICA substrates and samples. This method specifically identifies AFB1 and T-2 toxin, with detection limits of 0.01 ng/mL (0.20 μg/kg) and 0.02 ng/mL (0.40 μg/kg), respectively. Additionally, this approach uses a smartphone for imaging and an in-house developed intelligent system to read test line fluorescence signals, enabling quantitative point-of-care testing (POCT) measurements. Testing of maize samples showed recovery rates of 85 %-105 %, confirming the practical applicability of this method in food safety detection.