Figure 1 – A schematic diagram showing an example of a natural biological pigment (chlorophyll) with our target molecule beneath ‘Derivative Synthesis’ for applications as a fluorescent probe and/or activatable photosensitizer.
At the University of Maryland Baltimore County (UMBC) Department of Chemistry and Biochemistry the laboratory of Prof. Marcin Ptaszek is investigating the synthesis of novel molecular arrays, in specific, the chemistry and photochemistry of hydroporphyrins. Biological pigments such as chlorophylls and bacteriochlorophylls have advantageous photophysical properties that allow them and their derivatives to be used for an array of applications. Modern technological advances in medicine have increased accuracy in diagnosis and efficiency in treatment but a common struggle in medicine is the availability of accurate, real – time images to be used for either surgical procedures or diagnostic treatment plans. Most notably in the field of oncology, obtaining accurate images can be critical when excising tumor tissue while leaving healthy tissue intact. In addition, modern cancer treatments, such as photodynamic therapy (PDT), are still being extensively researched to assist in the efficiency of patient specific treatment plans.
This summer I joined the lab as a participant in National Science Foundation (NSF) Research Experience for Undergraduate (REU) program. My project aims to synthesize novel hydroporphyrin organoplatinum photonics materials and study their structure-photophysics relationship. This summer I have explored various synthetic pathways to produce a novel organoplatinum photonics material while generating other synthetically relevant precursors and compounds. Photochemical properties such as absorbance, fluorescence emission, and singlet – oxygen production have been studied to further gain an understanding of the chemical characteristics of our products.
Our focus on synthesizing novel hydroporphyrin derivatives has potential applications as activatable singlet oxygen photosensitizers to be used in PDT with possible applications in fluorescence imaging. This research combines the synthesis novel organoplatinum hydroporphyrin derivatives with the investigation of the structure – photophysics of such new materials. The addition of a heavy atom such as platinum (Pt) changes the electronic structure of the hydroporphyrin which influences properties such as intersystem crossing (ISC), quantum yield, as well as fluorescence and/or phosphorescence. By furthering our understanding of such processes and how they are manipulated by different substituents it is possible to bring the beneficial applications of hydroporphyrins from plants to people.