Preparation Of Carboxylated Upconverting Microrods And Their Application In Biological Detection

How to obtain encoded particle with high stability through a facile method is a key point for high throughput detection.In this study,carboxylated upconverting microrods were prepared through hydrothermal method.They showed unique optical advantage in application of biological detection.The contents are as follows:(1)Synthesis and characterization of upconverting microrods.Different reaction conditions were taken into account in the synthesis of upconverting microrods through hydrothermal method.SEM was utilized to represent the surface morphology and particle size of the microrods,and upconverting crystals with uniform size were prepared.(2)Preparation and characterization of the monodispersed upconverting microrods.Acid treatment was used to remove the surface ligand from upconverting microrods.Results from fluorescence microscope showed that free-ligand microrods were dispersed well in water and bright enough for observation by eyes.(3)Surface functionalization and characterization of upconverting microrods.St?ber method was used to form silica shell on the surface of microrods,after which PAA was introduced to surface for carboxylation.Results from TEM,FTIR and Zeta-potential instrument confirmed the carboxylation of the microrods.Coupling with fluorescent proteins further proved the effectiveness of the carboxylic groups for biological reaction.In addition,results from the fiber optical spectrometer showed that the microrods exhibited excellent stability of fluorescence against time and broad range of pH in solution.(4)Application of carboxylated upconverting microrods in immunoassay.Both microrods and encoded microspheres were performed in immunoassay.To be different with quantum dots encoded microspheres,identified reporting fluorescence was observed in the field of microscope.In addition,spectrum of the reporting signal exhibited its complete peak shape.The abovementioned results demonstrated that the carboxylated upconverting microrods with high stabile fluorescence were easily prepared.The microrods have great potential in application of biological detection due to their unique optical advantage.