Ledesma Francis, Nishitani Shoichi, Cunningham Francis J, Hubbard Joshua D, Yim Dabin, Lui Alison, Chio Linda, Murali Aishwarya, Landry Markita P
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA.
Innovative Genomics Institute (IGI), Berkeley, CA 94720, USA.
Adv Funct Mater. 2024 Aug 8;34(32). doi: 10.1002/adfm.202316028. Epub 2024 May 16.
Single-walled carbon nanotubes (SWCNTs) are desirable nanoparticles for sensing biological analytes due to their photostability and intrinsic near-infrared fluorescence. Previous strategies for generating SWCNT nanosensors have leveraged nonspecific adsorption of sensing modalities to the hydrophobic SWCNT surface that often require engineering new molecular recognition elements. An attractive alternate strategy is to leverage pre-existing molecular recognition of proteins for analyte specificity, yet attaching proteins to SWCNT for nanosensor generation remains challenging. Towards this end, we introduce a generalizable platform to generate protein-SWCNT-based optical sensors and use this strategy to synthesize a hydrogen peroxide (HO) nanosensor by covalently attaching horseradish peroxidase (HRP) to the SWCNT surface. We demonstrate a concentration-dependent response to HO, confirm the nanosensor can image HO in real-time, and assess the nanosensor's selectivity for HO against a panel of biologically relevant analytes. Taken together, these results demonstrate successful covalent attachment of enzymes to SWCNTs while preserving both intrinsic SWCNT fluorescence and enzyme function. We anticipate this platform can be adapted to covalently attach other proteins of interest including other enzymes for sensing or antibodies for targeted imaging and cargo delivery.
单壁碳纳米管（SWCNTs）因其光稳定性和固有的近红外荧光，是用于检测生物分析物的理想纳米颗粒。以往生成SWCNT纳米传感器的策略利用了传感模式对疏水SWCNT表面的非特异性吸附，这通常需要设计新的分子识别元件。一种有吸引力的替代策略是利用蛋白质对分析物的预先存在的分子识别来实现特异性，但将蛋白质连接到SWCNT以生成纳米传感器仍然具有挑战性。为此，我们引入了一个通用平台来生成基于蛋白质-SWCNT的光学传感器，并使用该策略通过将辣根过氧化物酶（HRP）共价连接到SWCNT表面来合成过氧化氢（H₂O₂）纳米传感器。我们展示了对H₂O₂的浓度依赖性响应，证实了该纳米传感器可以实时成像H₂O₂，并评估了该纳米传感器对H₂O₂相对于一组生物相关分析物的选择性。综上所述，这些结果证明了酶与SWCNT的成功共价连接，同时保留了SWCNT的固有荧光和酶功能。我们预计该平台可适用于共价连接其他感兴趣蛋白质，包括用于传感的其他酶或用于靶向成像和货物递送的抗体。
