Positioning of the sensor cell on the sensing area using cell trapping pattern in incubation type planar patch clamp biosensor

[Display omitted] ► Incubation type planar patch clamp overcomes the weak point of pipette patch clamp. ► It can realize high-throughput screening devices of neuron and neural network. ► Cell positing problem in planar patch clamp was solved by the cell trapping pattern. ► Reliable laser-gated ionchannel current was successfully observed. Positioning the sensor cell on the micropore of the sensor chip and keeping it there during incubation are problematic tasks for incubation type planar patch clamp biosensors. To solve these problems, we formed on the Si sensor chip's surface a cell trapping pattern consisting of a lattice pattern with a round area 5μm deep and with the micropore at the center of the round area. The surface of the sensor chip was coated with extra cellular matrix collagen IV, and HEK293 cells on which a chimera molecule of channel-rhodopsin-wide-receiver (ChR-WR) was expressed, were then seeded. We examined the effects of this cell trapping pattern on the biosensor's operation. In the case of a flat sensor chip without a cell trapping pattern, it took several days before the sensor cell covered the micropore and formed an almost confluent state. As a result, multi-cell layers easily formed and made channel current measurements impossible. On the other hand, the sensor chip with cell trapping pattern easily trapped cells in the round area, and formed the colony consisted of the cell monolayer covering the micropore. A laser (473nm wavelength) induced channel current was observed from the whole cell arrangement formed using the nystatin perforation technique. The observed channel current characteristics matched measurements made by using a pipette patch clamp.