Monodisperse and water-soluble LaF3/LaPO4∶ Ce, Tb nanocrystals via a microfluidic reactor for shape-control and bio-label

Microfluidic reactors with a design of steep temperature step or in microwave irradiation were utilized for preparation of LaF₃/LaPO₄: Ce, Tb nanocrystals using diethylene glycol (DEG) or ethylene glycol (EG) as solvent. Microfluidic reactor in special designs could separate the nucleation and growth of crystallization for shape-control and better bio-properties. The monodisperse and water-soluble LaF₃ nanoparticles consisted of well crystallized hexagonal phases with a shape of spherical and a mean diameter of about 4 nm with the highest photoluminescence quantum yield of 49%, promising for great potential application in bio-labels. Monodisperse LaPO₄: Ce, Tb nanorods have the length of 60-70 nm and diameter of 10-15 nm. Our results confirmed that it is possible to use some special designs such as a high temperature to burst nuclei and a low temperature to promote growth through a temperature step microreactor. Also it is in first time that using the combination of the microfluidic reactor and microwave irradiation to promote the crystallization and shape control for better bioapplications.