DNA mediated assembly of quantum dot–protoporphyrin IX FRET probes and the effect of FRET efficiency on ROS generation

Generation of Reactive Oxygen Species (ROS) by the irradiation of a photosensitizer is achieved in Photodynamic therapy (PDT) where controlled and targeted release of ROS by photosensitizer is crucial. This has been achieved with a ZnSe/ZnS quantum dots (QDs) donor and protoporphyrin IX (Pp IX) acceptor based fluorescence resonance energy transfer (FRET) probe. The QDs and Pp IX are assembled through DNA hybridization. The FRET efficiency was evaluated by steady- state and time- resolved spectroscopy. A single QD was found to host multiple number of Pp IX-DNA counterpart through DNA hybridization. FRET efficiency was found to increase with the increase in the number of Pp IX acceptors. ROS generation from Pp IX was affected by the irradiation time of the QD donor. This is reported in the journal Physical Chemistry Chemical Physics 2015 (DOI: 10.1039/c4cp05306k). This research has been performed by Dr. Prolay Das, Dr. Sahid Hussain and their research group in the department of Chemistry at IIT Patna in collaboration with BARC Scientist Dr. Manoj K. Singh.