Department of Chemistry, Malaviya National Institute of Technology, Jaipur, Jaipur 302017, India.
ACS Appl Bio Mater. 2021 Jan 18;4(1):252-266. doi: 10.1021/acsabm.0c01192. Epub 2021 Jan 4.
Concentrically arranged multilayered fullerenes exhibiting onion-like morphology are popularly known as carbon nano-onion (CNO) and are useful in bioimaging application. On the basis of the origin of the fluorescence, the CNO-based nanoprobes are classified into type I and type II. The type I CNO-based nanoprobe needs a secondary moiety such as organic dyes or an amine functionalization at its surface to induce the fluorescence. On the other hand, the emission in type II does not originate from such an external surface passivating agent. The CNO-based system not only shows structural similarity to the well-known multiwalled carbon nanotube but is also a bit more advantageous because of its low cytotoxicity. These features enable their prolonged use in the biological system for imaging purposes. In particular, we have covered the aspects of synthesis, surface functionalization, the origin of fluorescence, and biocompatibility. In addition, recent developments directed toward and imaging studies by utilizing CNO-based nanoprobes are summarized here.
同心排列的多层富勒烯呈现洋葱状形态，通常被称为碳纳米洋葱（CNO），在生物成像应用中很有用。根据荧光的起源，基于 CNO 的纳米探针可分为 I 型和 II 型。I 型基于 CNO 的纳米探针需要在其表面上添加有机染料或胺官能团等二级部分来诱导荧光。另一方面，II 型的发射并非源自这种外部表面钝化剂。基于 CNO 的系统不仅在结构上与著名的多壁碳纳米管相似，而且由于其低细胞毒性，还有一些优势。这些特性使其能够在生物系统中延长用于成像目的的时间。特别是，我们涵盖了合成、表面功能化、荧光起源和生物相容性等方面。此外，还总结了利用基于 CNO 的纳米探针进行和成像研究的最新进展。
