Measurement of cell electrical signal by dual-probe atomic force microscopy

The conduction of electrical signal plays critical roles in neuron activities. The capacity of atomic force microscopy to establish physical contacts at the nanoscale and offer higher spatial resolution compared to conventional electrical recording methods, such as patch clamp, significantly enhances our understanding and analysis capabilities. This capability enables the direct visualization and precise quantification of the electrical properties within specific cellular membrane regions. In this study, we use conductive probes in our self-developed dual-probe atomic force microscope system as nanoelectrodes to measure the electrical signals of SH-SY5Y cell. Given that SH-SY5Y cells exhibit neuron-like properties and are relevant to human neurological diseases, researching these cells provides valuable insights into neuronal behavior and pathology. In dual-probe atomic force microscope, one probe is responsible for sending stimulation signals to the cells, while the other probe receives transmitted information from the cell. By modulating the pressure applied by the tip to the cell membrane, the effects on SH-SY5Y cells at different contact depths and time intervals were investigated, along with the monitoring of cellular potential changes. The changes in cell potential were detected. Two different nonlinear electrical characteristics were observed, which indicate the cell membrane exhibits adaptability and self-repair ability, achieved by regulating the state of ion channels to ensure membrane potential stability. These results provide a new way to stimulate and study the electrical characteristics and physiological behaviors of cells and other biological samples, potentially revealing new insights of neuron activities.