To study the application value of sweet cherry leaves before abscission, a supercritical carbon dioxide (SFE-CO2) extraction method was established for sweet cherry (Prunus avium L.) leaves.

In this work, a simple, selective, and sensitive probe for hemoglobin based on the quenched fluorescence of silicon nanoparticles (SiNPs) was fabricated. The SiNPs were synthesized by a simple hydrothermal treatment from N‐[3‐(trimethoxysilyl)propyl]ethylenediamine and sodium citrate. The as‐prepared SiNPs exhibited good water‐solubility and high fluorescence with the quantum yield of 70%. The fluorescence of the SiNPs could be remarkably quenched by hemoglobin. A wide linear range was obtained from 50 nM to 4000 nM with a LOD of 40 nM. The quenching mechanism was investigated by UV‐Vis absorption spectrometry and time‐resolved fluorescence spectrometry.