Optical pH regulation using functional nanotool impregnating with photo-responsive chemical for intracellular measurement

We developed Optical pH regulation using functional nanotool impregnated with photo-responsive chemical for selective cell injection of nanotool. The nanotool was modified by fluorescent dye for intracellular measurement. The nanotool was included in the fusogenic liposome. Membrane fusion of the liposome to the cell membrane was used for invasive cell injection of the nanotool. The liposome fuses to the cell in weak acidic condition. Local pH regulation inside the liposome was developed using photochromic chemical for selective cell injection of the nanotool. The nanotool was modified by Leuco crystal violet (LCV). LCV emits the proton by ultraviolet (UV) illumination. The emitted proton decreases the pH value in the liposome. This pH regulation is reversible by UV/VIS illumination. The liposome was manipulated by optical tweezers. After contact of the liposome to the cell, the liposome was adhered to the cell by UV induced membrane fusion. Injected nanotool was manipulated by optical tweezers. Intracellular temperature was detected by measuring the fluorescence intensity of the nanosensor. We demonstrated optical pH regulation, selective cell injection of the nanotool, and manipulation of the nanotool in the cell.