Hybrid metal–organic framework (MOF)-derived core–shell structured nanoporous carbon (CS-NPC) and multi-walled carbon nanotube (MWCNT)-based novel nanocomposite (CS-NPC@MWCNT) were introduced as solid contact (SC) material in an electrochemical patch for sensing sweat electrolytes. The SC-based sensors demonstrated an excellent Nernstian response owing to the remarkable ion-to-electron transduction, significant surface area (357 m2.g−1) with graphitic electrical conductivity, and high specific capacitance (270 F.g−1) properties of the SC material. CS-NPC@MWCNT nanocomposite effectively formed a high double-layer capacitance and minimized the formation of an aqueous layer due to its hydrophobic property (water contact angle 135°). The fabricated patch, with a miniaturized printed circuit board and microfluidic sweat collection channel, and finally incorporating a correction algorithm that considers pH changes to obtain a more accurate quantification enabled the real-time on-body monitoring of sweat. This study paves the way for connecting a wide range of MOF-derived nanoporous carbon materials for use as transduction materials in various sensing applications.