A capillary device made by aptamer-functionalized silica photonic crystal microspheres for the point-of-care detection of Ochratoxin A

Abstract

Abstract Ochratoxin A (OTA) is one of the mycotoxins widely found in various cereals, development of a simple, low-cost, and point-of-care detection technique is urgently needed to protect human from OTA threat by food chains. Here, a point-of-care analytical device targeting OTA was developed based on a capillary column packed with silica photonic crystal microspheres (SPCMs). The SPCMs were modified with fluorophore-labeled aptamers for the specific recognition of OTA. A monolithic plunger in the capillary column was made and could improve the detection sensitivity and accuracy. The designed capillary device was able to automatically extract target molecules based on capillary force, and could realize the point-of-care detection through the fluorescence detection on column directly. Moreover, the capillary device could achieve repeated tests at one time in a single column. Finally, the point-of-care device was successfully applied for the OTA detection in cereals, giving a broad linear detection range of 1–100\u2009ng/mL and a high-quality recovery rate of 86–108 %, and just requiring a small sample volume of 2\u2009μL per SPCM. The point-of-care analytical device could also be expanded for the multiple target molecules screening detection by using SPCMs that were modified with different mycotoxins aptamers.