Enhancing the performance of photonic DNA nanomachines for implementing photonic nanoscale automaton

摘要

Development of nanoscale computers that can manipulate molecular information directly is an important issue in nano-engineering. To meet the demand, we are studying on nanoscale automaton based on photonics and DNA technology. This method enables us to achieve information processing using propagating light with a resolution higher than that determined by the diffraction limit. Use of the propagating light offers, in particular, spatially parallel operation of nanoscale automata and utilization of spatial information. As an example of photonic nanoscale automaton, we demonstrated a self-contained DNA nanomachine that is controlled through optical input, although the performance of the operation was not high enough as nanoscale automaton. This photonic DNA nanomachine contains azobenzene-tethered DNA to be controlled through photoisomerization of the azobenzene induced by photonic signal. It is transited to the open-state after ultraviolet light irradiation (cis-form), and to the closed-state after visible-light irradiation (trans-form). In this study, we investigate the operating conditions including the wavelength and bandwidth of irradiation light and the temperature to improve the performanc'e of the DNA nanomachine. Experimental results show that the state of the DNA nanomachine can be changed in less than one minute, which is one-tenth shorter than the previous result, with little decrease in efficiency during ten transition cycles. The transition rate was estimated about hundreds transitions/sec in a volume of 1 cubic micrometer. This suggests that photonic DNA automaton based on the DNA nanomachine can be operated using spatially-parallel photonic signal input.