Fig. 3: Fabrication and characterizations of COF-silk microneedles.
From: Chromatic covalent organic frameworks enabling in-vivo chemical tomography
A Optical microscope image of TSMN700. B SEM images of tip-broken TSMN700 that depict the TAPP-TFPA outer layer. C Illustrations and SEM images of TSMN250, TSMN450, and TSMN700. D Relative height (defined as the ratio between the length of the segment that depicted a color change (h) and total length (H)) is equal to the relative diameter (defined as the ratio between the diameter of the color changed inner circle (d) and the total diameter (D)) observed from a top view. (E) Top and side views of TSMN700 inserted into a transparent alkaline gel. TSMN700 was pretreated with pH = 4.5 buffer. Alkaline gel has a pH of 9.0. F Relative diameter and relative height of color changed microneedle part presents a linear relationship. In A–C, E images are representative of at least three independent experiments.
