Evaluation of photoinduced color changing fluorophore for a biosensor

• Main Authors: Jung-Chih Lin, 林容至
• Other Authors: 張健忠
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/70013677580204869452

碩士 === 國立中興大學 === 生醫工程研究所 === 100 === In this study, we focused on the therapy and diagnosis of cancers. Three binary molecule conjugates were designed and synthesized by conjugating a chromophore (3,6-bis-(1-methyl-4-vinylpyridinium)-carbazole diiodide, BMVC) to mono-, bis- and trishydroxyl photosensitizers, respectively. For this binary system, BMVC plays the role of cancer cells recognizer; fluorescence resonance energy transfer (FRET) donor to porphyrins, and also enhance the efficient of photodynamic therapy (PDT). In addition, the intracellular fluorescent colors switching upon photo-excitation are expected to be used for further cell death biomarker applications. Therefore the binary system was successful to apply the FRET effect to PDT, also killed the cancer cells selectively.Base on the study above, fluorescent color switching in cells is important for cancer cell recognization. Here, a pH-dependent fluorescence emission compound, 2-(6-(4-aniline)-1, 3-dioxo-1-H-benzo [de]isoquinolin -2(3H)-yl)-N,N-dimethyl-ethanamine (ADA), was designed and we investigated the excited state proton transfer (ESPT) behaviour when irradiation. The fluorescent intensity quenched once the compound ADA was protonated while irradiation resulted in emission blue-shift and intensity enhancement due to the ESPT. When cells were treated with ADA, the fluorescent intensity in normal cells is much higher than cancer cells due to their different degree of pH environment. On the other hand, intracellular fluorescent colors switching upon irradiatting. It hints that ADA is expected to become a normal cell biomarker as well as the control brackground in calculation the percentage of cancer cells in whole tissue.