Nanoscale Sensors for Multi-Modal Detection of Genotoxic Agents
Daniel A. Heller1, Hong Jin, and Michael S. Strano2. (1) Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 66-565, Cambridge, MA 02139, (2) 66-566 Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139
Reactive oxygen species (ROS) and active alkylating chemotherapeutics are important bioanalytes but difficult to measure selectively, in vivo, or in real time. A new nanoscale optical sensor platform under development can detect as well as identify these analytes in situ. Carbon nanotube-DNA complexes, formed by individually encapsulating nanotubes with oligonucleotides, respond in real time to these agents via multiple optical modes, giving each analyte a distinct optical signature. Single-walled carbon nanotubes are environmentally sensitive and emit tissue-transparent near-infrared photoluminescence. By their encapsulation in short strands of synthetic DNA, we introduce a selective handle for changing their emission, allowing detection of DNA-damaging oxygen species or alkylating agents, by red-shifts in emission energy as well as optical quenching, giving multiple detection modes which result in analyte specificity. The nanotube-DNA complexes exhibit uptake into mammalian cells via endocytosis without cytotoxic effects and transduce analyte activity information live and in situ.