Photoacoustic Microscopy Based On Multi-function Organic Molecule Probe

Photoacoustic imaging is a new type of non-invasive biomedical imaging technology with the advantages of high contrast of pure optical imaging and large penetration depth of pure ultrasound imaging,and has received extensive attention in the field of medical imaging in recent years.Compared with other optical imaging technologies such as fluorescence imaging technology,photoacoustic imaging has a relative sensitivity of 100% for absorption,which can not only detect endogenous absorbers such as hemoglobin for high-resolution in vivo images,but can also be used for exogenous contrast agents imaging/detection,thereby providing a new technical mean for the early diagnosis of human diseases.In this thesis,we designed and built an oblique-detection optical-resolution photoacoustic microscope(OR-PAM)imaging system.The system is simple in structure and easy to adjust.The lateral spatial resolution of the system is 3.5 ?m,and can be used for in vivo mouse ear and cerebral cortex imaging.Combined with the above system,we used the Dye-Cu and WW-1-80 molecular probes for photoacoustic detection of copper ion concentration and pH value.For the detection of copper ion concentration,we used the probe molecule Dye-Cu with absorption dependent on the copper ions concentration and achieved a detection limit of 0.1 mmol /L.For pH detection,we have designed and synthesized a new type of pH-sensitive molecular probe WW-1-80 and prepared buffers with different pH values to simulate the microenvironmental changes in biological tissues.By analysis of the photoacoustic signal strength from the mixed solutions of different pH buffers and WW-1-80,We have realized the detection of the microenvironment pH values.Based on the above in vivo mouse imaging and the detection of copper ion concentrations and pH values,the OR-PAM system demonstrated in this work is promising to detect the copper ion concentration and pH value in the tissue in the future,and to be used for development of new molecule probes and early diagnosis of humanrelated diseases.