Fluorescence Imaging Of CLE19Peptide Receptor On Plant Cell Surface Using Functional Nanoparticles As Probes

As novel fluorescent nanomaterials, quantum dots (QDs) and noble metal (Au and Ag) nanoclusters (NCs) have widespread applications in chemical detection, biosensing, target imaging and disease diagnose. However, investigations of fluorescence imaging of plant cell by using QDs and NCs as probes are extremely limited. This motivated us to build fluorescent probes based on QDs and NCs and use them to target the CLE19peptide receptor on the surface of plant cell. The main contents are listed as follow:1. The CLE19peptide composed of NH2(CH2)6RVIPTGPNPLHN (abbreviated as P1) and CCYRVIPTGPNPLHN (abbreviated as P2) was coupled with GSH-CdTe QDs by covalently connection and direct absorption effect, respectively. The optical properties of these fluorescent CdTe QDs probes were investigated by fluorescence (FL), ultra-violet visible (UV-vis) and resonance light scattering (RLS) spectroscopy. The Columbia Arabidopsis was planted and the protoplasts from mesophyll were enzymatically prepared. The fluorescent probes of CdTe QDs were utilized to target the CLE19peptide receptor on the surface of Arabidopsis protoplast.2. The fluorescent Au NCs and Ag NCs were biomimetic synthesized with P2as an efficient template. The optical properties of these NCs were characterized by FL, UV-vis and dynamic light scattering (DLS) spectroscopy. The result showed that both Au NCs and Ag NCs emitted green fluorescence and could serve as a candidate for imaging. After co-culture with Arabidopsis protoplasts, Au NCs could be exploited to probe the CLE19peptide receptor on the surface of Arabidopsis protoplast.3. The interaction of histidine-capped Au NCs with BSA has been investigated by FL, UV-vis, circular dichroism (CD) and Raman spectroscopic techniques under simulative physiological conditions. The results showed that the fluorescence of BSA was quenched by Au NCs and the quenching mechanism was discussed to be a dynamic quenching style. It indicated that hydrophobic force played a key role in the interaction process. Further results from the CD spectra and Raman spectra demonstrated that the a-helical content in BSA was reduced upon interaction with Au NCs which induced a partial protein destabilization. This study contributes to a better understanding of the biology toxicity of Au NCs to biomolecular, which is very essential for the development of safe and functional Au NCs.