Fluorescent silicon nanoparticle–based quantitative hemin assay

Hemin with functions such as oxygen carrying, oxygen storing, promoting redox, and performing electron transfer is important for the health of organisms. In this paper, green synthetic silicon nanoparticles (Si-NPs) were synthesized and used for free hemin detection in serum (a low limit of detection (LOD), 29.5 nM). The quenching mechanism was investigated by UV–vis absorption spectra, time-resolved luminescence decay curve, and circular dichroism (CD) spectra. It was confirmed that multiple redox centers of hemin led to intensified effective collision and increased the electron transfer rate, therefore enhancing the dynamic quenching, and it was undeniable that the inner filter effect (IFE) also played a role in the quenching. Graphical abstract