This work presents a novel multi-marker sensor platform integrating a silicon nanowire (SiNW) junctionless field-effect transistor (JLFET)-based pH sensor and an amperometric lactate sensor on a single chip, fabricated using a CMOS-compatible top-down process. Real-time, multiplexed detection of lactate and pH is demonstrated using a multichannel electrochemical readout integrated circuit. The platform delivers reliable sensing in low-volume samples as small as 15 μl, offering current sensitivities of 51 μA/mM/cm2 for lactate and 18 nA/pH for pH, while showing negligible crosstalk. The reported results underscore the platform's potential for compact, wearable biosensing applications that harness system-on-chip technology to enable continuous, real-time multi-biomarker monitoring in serum or interstitial fluid, paving the way for personalized healthcare and disease management.