la9b03960_si_001.pdf (1.37 MB)
Orthogonal Adsorption of Carbon Dots and DNA on Nanoceria
journal contribution
posted on 2020-02-25, 22:13 authored by Chunmei Li, Jinyi Zhang, Hui Jiang, Xuemei Wang, Juewen LiuCarbon
dots (CDs) are highly fluorescent nanomaterials with surface
carboxyl and amino groups. However, their exact structure remains
under debate. In this work, we probed the surface properties of CDs
by physically adsorbing them onto various nanomaterials. Three types
of nanomaterials, including CeO2 nanoparticles (nanoceria),
gold nanoparticles, and graphene oxide were tested. Among them, nanoceria
strongly adsorbed the CDs and quenched their fluorescence. For the
tested anions to compete with the CDs for adsorption, only phosphate
and F– induced desorption of the CDs from nanoceria,
and the phosphate-induced desorption was less compared to that by
F–. This was opposite to the desorption of DNA from
nanoceria, where phosphate induced more DNA desorption. Furthermore,
using calcein and fluorescein as representative dyes for comparison,
we conclude that the CDs might use their carboxyl groups to adsorb
on nanoceria, while DNA uses its phosphate backbone for adsorption.
This difference may explain their occupying different surface sites
on nanoceria and different displacement by phosphate and F–. Using nanomaterials as probes to understand the surface properties
of CDs is effective, and such understanding might in turn be used
for building hybrid materials for applications.