Surface-Enhanced Raman Scattering And Colorimetry Dual-Mode PH Monitor Based On Gold Nanorods@Polyaniline-Embedded Gel Microparticles

The acidity of biological microenvironments plays an important role in human body.The acidity of the microenvironments not only affects the occurrence,malignant transformation,metastasis and angiogenesis of tumors,but also affects the response of cancer cells to various treatments.Therefore,it is of great significance to monitor the acidity of tumor microenvironments.In this paper,based on the change of Raman signal intensity and color caused by protonation and deprotonation of polyaniline at different pHs,a colorimetry and surface-enhanced Raman scattering(SERS)dual-mode pH sensing method based on gold nanorod@polyaniline(AuNRs@PANI)-embedded polyethylene glycol diacrylate microparticles(PEGDA)was proposed.SERS signal was enhanced by coating AuNRs with PANI.The stability and sensitivity of the sensor was enhanced by encapsulating AuNRs@PANI with PEGDA.The pH change of culture medium during cell culture was monitored by using the dual-mode pH sensor.In chapter 1,firstly,the significance of detecting biological microenvironment pH and the main detection methods of pH were introduced.The applications of gold-polyaniline nanocomposites in SERS sensing were reviewed.Secondly,the preparation methods and applications of gel microparticles were introduced.Finally,the significance and design ideas of this work were put forward.In chapter 2,AuNRs@PANI nanoparticles were prepared firstly.Then AuNRs@PANI/PEGDA gel microparticles were prepared on a microfluidic chip.AuNRs@PANI nanoparticles were characterized by Raman spectroscopy,absorption spectroscopy and transmission electron microscopy.AuNRs@PANI/PEGDA microparticles were characterized by optical imaging and Raman spectroscopy.SERS signal and color change of AuNRs@PANI/PEGDA gel microparticles under different pHs were used to realize pH monitoring of cell culture environment.The SERS detection method has good linearity within pH 5.4-8.0.The fitting curve is y=-5707.46+1164.96x(R2=0.995).AuNRs@PANI/PEGDA also exhibited vivid color change within the physiological pH range 5.5-8.0,and was used to visualize pH change with a precision of 0.5 pH unit.In chapter 3,the colorimetry and SERS dual-mode pH detection method based on AuNRs@PANI/PEGDA gel microparticles was summarized,and its application was prospected.