Novel Chiral, Water-Soluble SiQDs for Sensitive ONOO- Detection: A Melanin-Like Precursor Approach

A chiral, water-soluble and ONOO- sensitive SiQDs with a melanin-like precursor has been reported for the first time. The SiQDs-(K/L-P)ox were selected after comparing the optical properties of SiQDs-(K/L-P)ox and SiQDs-(K/D-P)ox to examine their ability to detect ONOO-. SiQDs-(K/L-P)ox can detect fluctuations in the concentration of ONOO- through the 'fluorescence off' phenomenon, as KYF tripeptide can be oxidized by ONOO-. The results demonstrate that SiQDs-(K/L-P)ox has a good linear detection range for ONOO- with a range of 2-10 and 20-100 μM, and a LOD of 99 nM (n = 3). Additionally, SiQDs-(K/L-P)ox has low toxicity and high biocompatibility for HepG2 cells. The endogenous ONOO- produced in mitochondria and lysosomes in HepG2 cells can be examined by observing the variety of yellow fluorescence intensity at the 514 nm channel. In principle, the SiQDs-(K/L-P)ox probe should be useful in detecting a variety of inflammation-related diseases.