NaYF 4:Yb/Tm based all-purpose up-conversion fluorescence probe for high sensitive organics detection

Many organics are dangerous to environment as well as precise electronic devices. Detection of organics is a big challenge due to huge amount of species of organic materials. This is because specific fluorescence probe is needed in order to detect a kind of specific organic material. This makes it impossible to develop specific fluorescence probe for each kind of organic material. As a result, development of an all-purpose fluorescence probe, which is high sensitive to different types of organics, is of crucial importance. In this work, we report an all-purpose up -conversion fluorescence probe for high sensitive detection of different species of organic materials. Surface functional groups -COOH, which help to alter electrons transition (alter emission intensity ratio I 348/364 ) of rare earth materials doped upconversion micro -particles (UCMPs), are key to the all -purpose upconversion fluorescence probe. Intensity response of I 348/364 is detected to be as low as 3*10 -10 and 8*10 -10 g to water and oil by a single excitation, respectively. As a result, chemicals remain on a piece of paper by finger touch can be detected by this upconversion fluorescence probe. High sensitive detection of different species of organic materials are also demonstrated in this work. This findings pave the way of all-purpose sensors development.