fig4

Figure 4. Microneedle-based implantable E-AB sensor platforms and sensing mechanisms. (A) Wearable microneedle-based E-AB sensor schematic. Reprinted with permission^[115]. Copyright 2023, Elsevier; (B) Conventional and wearable TDM comparison, with μNEAB-patch illustration and process flow. Reprinted with permission^[95]. Copyright 2022, American Association for the Advancement of Science; (C) Dual-sensing microneedle platforms: HMN-Flex and HMN-pH. Reprinted with permission^[118]. Copyright 2024, John Wiley and Sons; (D) Point-of-care biosensing strategy for multi-analytes. Reprinted with permission^[121]. Copyright 2023 John Wiley and Sons; (E) μSMART system for CRP detection. Reprinted with permission^[122]. Copyright 2025, American Chemical Society. TDM: Therapeutic drug monitoring; ISF: interstitial fluid; MB: methylene blue; HMN: hydrogel microneedle; HMN-RR: hydrogel microneedle-phenol red; DAHA: dopamine-based hyaluronic acid; CRP: C-reactive protein; E-AB: electrochemical aptamer-based.