(A) Study on photothermal cell lysis on gold nanograils for single cell analysis

Abstract

We have demonstrated photothermolysis of pathogenic bacteria, Staphylococcus aureus, in gold nanograils of plasmonic nanostructures. Gold nanograils characterized by three sharp rings have a good tunability of multiple plasmon resonances. We fabricated the gold nanograils via colloidal lithography changing a few processing parameters to match LSPR wavelength to NIR region (to match the wavelength of laser irradiation). Furthermore, for single cell arrays, the ring size was made comparable to the bacteria size. With Gold nanograil which can provide isolated space for a single bacterium, each bacterium was captured on a gold nanograil by several methods; chemical, electrostatic, and physical methods. The most efficient method was shown to be a physical method using centrifugal force. Finally, bacteria captured in the gold nanograil were lysed by using tunable Ti;Sapphire laser with a peak wavelength at NIR region. We expect that this lysis technique enables analysis of the single cell in a microfluidic chip without any reagents or equipment.