Long-Lasting\nChemiluminescence Based on Functionalized\nMulticolor Protein Capsules for Multiple Visualization Detection of\nAvian Influenza Virus Biomarkers

Long-lasting chemiluminescence (CL) emissions are necessary\nfor\nimproving the detection accuracy and expanding the application scope.\nHere, we have synthesized three oil-in-water (O/W) multicolor protein\ncapsules (LCBA, F/LCBA, and RB/F/LCBA) using a simple ultrasound method\nand have engineered specific target-triggered catalytic hairpin assembly\non their surface and chemiluminescence resonance energy transfer inside.\nConsequently, three multicolor capsules exhibit excellent structural\nstability, generate blue-, green-, and red-colored emissions when\nreacting with H<sub>2</sub>O<sub>2</sub>, have long-lasting CL emission\nover 1 h, and successfully achieve the accurate multiple visualization\ndetection of avian influenza virus subtype targets. Without the need\nfor complex instruments and analysis procedures, the CL imaging assays\ncan be carried out and recorded with a common smartphone. The detection\nlimits for visualizing H1N1, H7N9, and H5N1 are 5.5, 7.6, and 9.0\npM, respectively. There is a linear range between 20.0 and 625 pM\nand excellent selectivity against interfering DNA. Furthermore, visualization\ndetection has been successfully applied for the detection of H1N1,\nH7N9, and H5N1 in healthy human serum samples. With these merits,\nthis facile, ultrasensitive, and multiple visualization sensor has\npotential applications in point-of-care testing and early diagnosis.