posted on 2020-04-01, 21:13authored byLi Lei, Min Li, Sufen Wu, Zhiai Xu, Ping Geng, Yang Tian, Ying Fu, Wen Zhang
Development of probes
for accurate sensing and imaging of biometals in situ is still a growing
interest owing to their crucial roles in cellular metabolism, neurotransmission,
and apoptosis. Among them, Zn2+ and Cu2+ are
two important cooperative biometals closely related to Alzheimer’s
disease (AD). Herein, we developed a multifunctional probe based on
self-assembling peptide nanoribbon for ratiometric sensing of Zn2+, Cu2+, or Zn2+ and Cu2+ simultaneously. Uniform peptide nanoribbon (AQZ@NR) was rationally
designed by coassembling a Zn2+-specific ligand AQZ-modified
peptide (AQZKL-7) with peptide KL-7. The nanoribbon further combined
with Cu2+-sensitive near-infrared quantum dots (NIR QDs)
and Alexa Fluor 633 as an inner reference molecule, which was endowed
with the capability for ratiometric Zn2+ and Cu2+ imaging at the same time. The peptide-based probe exhibited good
specificity to Zn2+ and Cu2+ without interference
from other ions. Importantly, the nanoprobe was successfully applied
for noninvasive Zn2+ and Cu2+ monitoring in
both living cells and zebrafish via multicolor fluorescence imaging.
This gives insights into the dynamic Zn2+ and Cu2+ distribution in an intracellular and in vivo mode, as well as understanding
the neurotoxicity of high concentration of Zn2+ and Cu2+. Therefore, the self-assembled nanoprobe shows great promise
in multiplexed detection of many other biometals and biomolecules,
which will benefit the diagnosis and treatment of AD in clinical applications.