Compact Magneto‐Fluorescent Colloids by Hierarchical Assembly of Dual‐Components in Radial Channels for Sensitive Point‐of‐Care Immunoassay. Issue 25 (25th May 2021)

• Record Type: Journal Article
• Authors: Huang, Liang; Zhang, Yuxing; Liao, Tao; Xu, Kui; Jiang, Chenxing; Zhuo, Dinglv; Wang, Yang; Wen, Hui‐Min; Wang, Jing; Ao, Lijiao; Hu, Jun
• Is Part Of: Small. Volume 17:Issue 25(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-25
• Subjects: assembly -- fluorescence -- immunoassay -- magnetic‐separation -- mesoporous templates; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202100862
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Exploring signal amplification strategies to enhance the sensitivity of lateral flow immunoassay (LFIA) is of great significance for point‐of‐care (POC) testing of low‐concentrated targets in the field of in vitro diagnostics. Here, a highly‐sensitive LFIA platform using compact and hierarchical magneto–fluorescent assemblies as both target‐enrichment substrates and optical sensing labels is demonstrated. The large‐pored dendritic templates are utilized for high‐density incorporation of both superparamagnetic iron oxide nanoparticles (IOs) and quantum dots (QDs) within the vertical channels. The hierarchical structure is built via affinity‐driven assembly of IOs and QDs from organic phase with silica surface and mercapto‐organosilica intermediate layer, respectively. The sequential assembly with central–radial channels enables 3D loading of dual components and separately controlling of discrete functionalities. After the alkyl‐organosilica encapsulation and silica sealing, the composite spheres exhibit high stabilities and compatibility with LFIA for procalcitonin (PCT) detection. With the assistance of liquid‐phase antigen‐capturing, magnetic enrichment, and fluorescence‐signal amplification, a limit of detection of 0.031 ng mL −1 for PCT is achieved with a linear range from 0.012 to 10 ng mL −1 . The current LFIA is robust and validated for PCT detection in real serum, which holds great diagnostic significance for precise guidance of antibiotic therapy with POC manner. Abstract : The controlled co‐incorporation of bi‐components within central–radial channels is achieved via template‐based hierarchical assembly strategy. The compact loading of both nano‐units in 3D template space ensures a strong superparamagnetic response and high fluorescent brightness of single colloid. A highly sensitive point‐of‐care immunoassay of procalcitonin is established by integrating magnetic antigen‐enrichment and fluorescent signal enhancement using the magneto–fluorescent dual‐functional labels.