Laser-driven gel microtool for single-cell manipulation based on temperature control with a photothermal conversion material

Abstract

We propose a laser-driven hybrid gel microtool for stable single-cell manipulation. The microtool is made of a microbead dyed with multiwalled carbon nanotubes (MWNT) and thermosensitive poly (N-isopropylacrylamide) gel coating. The gel adheres to cells at high temperatures but not at low temperatures. We can manipulate single cells without direct laser irradiation by adhering the cells to the gel on the microtool using the cell-adhesion property of the gel. The microtool is heated by trapping it with optical tweezers to make its surface cell-adhesive during the manipulation. Furthermore, we can control the optical heating property of the microtool by dyeing the microbeads with MWNT ink. The laser-heating-induced temperature increase of the microtool can be controlled from 4.2 °C to 23.5 °C by varying the concentration of MWNT ink. We succeeded in fabricating the proposed microtool and demonstrated single-cell transportation using the microtool without direct laser irradiation of the cell.