Fig. 4. In vivo continuous glucose monitoring (CGM) using a biodegradable microneedle sensor.

(A) In vivo setup image of the continuous glucose measurement with a mouse model: (1) digital camera with a long-pass filter lens, (2) lamp, (3) mouse with an inserted microneedle glucose sensor, and (4) glucometer. (B) Fluorescence photograph of the microneedle sensor attached to the mouse model. A 405-nm lamp and a 450-nm long-pass filter were used. (C) Image analyzed using ImageJ. (D to G) In vivo results obtained using a biodegradable microneedle glucose sensor and a glucometer (black, relative fluorescence intensity; red, glucose concentration measured by the glucometer). The CGM results were measured on day 0, day 1, day 2, and day 3. a.u., arbitrary units.