Researchers from the Institute of Chemistry, Chinese Academy of Sciences (CAS), have made important breakthroughs in achieving silica-coated CdTe QDs – CdTe@SiO2 nanoparticles – with extremely high fluorescence quantum efficiency. By manipulating the interactions among the encapsulated QDs, CdTe@SiO2 composite particles with a multi-core structure have been developed, which turn out to be an effective measure for increasing the fluorescence brightness. Building on this work, the team has recently produced surface biofunctionalized multi-core/shell CdTe@SiO2 particles for cancer cell detection.

To construct the cancer cell probes, polyethylene glycol and carboxyl groups are introduced simultaneously to the particle surface for anti-biofouling and bioligand conjugation purposes. By covalently conjugating a goat anti-human immunoglobulin G (GaHIgG) antibody to the particle surface via amidation reaction, a cancer cell probe has been developed and successfully used to detect the UM-SCC-22B human head and neck squamous cell carcinoma cell line cells via indirect fluorescent antibody assay (IFA).

In comparison with direct fluorescence antibody assay, IFA allows for significant fluorescence signal amplification in spite of the multi-step procedures and enhanced nonspecific signals. Moreover, IFA is technically meaningful for product development.

The group believes that its current investigations pave the way for simultaneously introducing anti-biofouling coating and surface reactive residues to the silica-coated CdTe QDs. Yet, the techniques are not just limited to cell labeling, they also hold promise for many other bioapplications.

Full details can be found in the journal Nanotechnology.