Aminodextran-coated potassium niobate (KNbO3) nanocrystals for second harmonic bio-imaging

Potassium niobate (KNbO3) nanocrystals exhibiting good second harmonic generation properties were coated with dextran derivatives containing primary amine groups. The surface modification results from attractive electrostatic interaction between the aminodextran molecules and the negatively charged surface of bare KNbO3 nanocrystals. To avoid flocculation, a suspension of KNbO3 nanocrystals was firstly prepared and then added drop-wise to an aqueous solution of aminodextran. The as-prepared hybrid (AD-coated KNbO3) nanoparticles were then characterized by using various techniques including transmission electron microscopy (TEM), infrared analysis (FTIR), dynamic light scattering (DLS) and zeta potential measurements as a function of pH of the dispersion medium. Then, the prepared AD- coated KNbO3 nanoparticles were evaluated in vitro diagnostic application as biomarker for non-tumor lung-derived human cells. The obtained results showed that the aminodextran-coated KNbO3 nanoparticles were efficiently bound to the non-tumor lung-derived human cells, which was proved by using a commercial Nikon multi-photon imaging platform. In addition, AD-coated KNbO3 nanoparticles showed good optical contrast for the investigated cells, and consequently they can be efficiently used as contrast agents in the bio-imaging diagnostic domain.