Phosphate source induced rapid synthesis of urchin-like hydrated GdPO4:Eu3+ nanoparticles: Imaging and drug delivery in A549 cell line

Abstract

Energy and environmental concerns are increasing owing to the increased consumption of resources. To help solve the energy crisis and contribute to protecting our environment, this study aimed to develop a fast and eco-friendly method of synthesis. We propose a H3PO4 assisted fast synthesis technique for developing urchin-like GdPO4·xH2O:5Eu3+ nanoparticles. First, Gd(OH)CO3:5Eu3+ nanospheres with sizes of about 60 nm were developed using urea-based homogeneous precipitation. These nanospheres were utilized as the Gd3+ source and sacrificial templates in the formation of urchin-like GdPO4.xH2O:5Eu3+ nanoparticles, where the Kirkendall effect takes place during hydrothermal synthesis. The structural properties confirmed the existence of the H2O phase in the GdPO4:5Eu3+ nanoparticles. The synthesized urchin-like GdPO4·xH2O:5Eu3+ nanoparticles exhibited excellent photoluminescence in the reddish-orange region upon excitation by near-UV excitation wavelengths. These urchin-like nanoparticles demonstrated effective penetration in lung cancer cells by exhibiting luminescence from both the cytoplasm and nucleoplasm. The conjugation of doxorubicin with urchin-like GdPO4·xH2O:5Eu3+ nanoparticles helped to realize efficient antitumor activity against lung cancer.