Surfactant-Boosted Silk Fibroin Microneedle Patches for Visual Glucose Detection

Abstract

Silk fibroin (SF) has demonstrated great potential in diagnostics due to its excellent biocompatibility and biodegradability. Used as microneedles (MNs), SF is a compelling option for constructing an adaptable catalyst diagnostic platform due to its high integration. However, the defective hardness and swelling of SF MNs confine further catalyst-based visional detection. Herein, we present a facile approach involving the β-sheet induction by a nonionic surfactant, Tween 20, posing an on-demand regulation of SF MNs for further visual detection. Compared with the usual nonionic surfactants (Tween 80, PEG, and PEGMSE), Tween 20 demonstrated a remarkable ability to induce β-sheet formation within SF, which subsequently could facilitate the distinctive hardness (>1.06 N/needle) and swelling (60−180%) for SF MNs. Then, the agarose-based glucose model was used for visual detection, and consequently, the glucose oxidase (GOx)-HRP-TMB-integrated SF MN patch demonstrated a significant colorimetric quantitation as glucose concentration within 25−600 mg/dL (R 2 = 0.99304). More generally, the visual detection of glucose in types of fruits revealed the high efficacy and accuracy of the SF MN patch (R 2 = 0.94724), further indicating the advantage of Tween 20-tailored SF MNs as a visual platform. These achievements provide a facile tactic to reach an alternative hardness and swelling regulation by one step for catalyst implanted based SF MNs, further revealing the great potential of SF MNs for visual diagnostic.