Coating Fe₃O₄ quantum dots with sodium alginate showing enhanced catalysis for capillary array-based rapid analysis...

A simple and high-throughput colorimetric analysis array has been constructed for quantifying H₂O₂ in milk using Fe₃O₄ quantum dots (QDs), which were coated with sodium alginate (SA) and chromogenic substrate onto the arrayed capillary tubes. It was discovered that the Fe₃O₄ QDs could present larger peroxidase-like catalysis than Fe₃O₄ nanoparticles (NPs). Particularly, dramatically enhanced catalysis activity could be achieved for Fe₃O₄ QDs if coated with SA films. Moreover, the use of SA could protect Fe₃O₄ QDs to expect the improved environmental stability. A capillary arrays-based high-throughput colorimetric platform was thereby developed for the detection of H₂O₂ in milk, with levels linearly ranging from 10 to 400 μM. Importantly, the developed colorimetric platform with the capillarity power for automatic fetching of multiple samples may promise the practical applications for extensive monitoring of multiple H₂O₂ samples for food safety.