Vancomycin (Van), a widely utilized glycopeptide antibiotic in clinical settings, necessitates precise bloodstream concentration monitoring due to its narrow therapeutic window, ensuring drug efficacy while preventing adverse effects. In this work, we have engineered an extended-gate field-effect transistor (EG-FET) sensor tailored for vancomycin detection. This novel sensor configuration comprises a detachable multi-doped graphene EG electrode sensing element paired with a commercial field-effect transistor (FET). The EG electrode design integrates a sophisticated multistage doping process, incorporating MnO and Au nanoparticles into laser-induced graphene (LIG), thereby augmenting both functional and electrical characteristics of LIG. To achieve specific recognition, a vancomycin aptamer is immobilized onto the electrode surface, enabling selective binding with vancomycin and translating this interaction into a measurable electrical signal. This collaborative mechanism empowers the EG-FET sensor to exhibit exceptional sensitivity and selectivity towards vancomycin. Notably, the sensor demonstrates a wide linear response ranging from 1 nM to 100 μM, spanning the entire therapeutic window of vancomycin (6-35 μM), boasting an impressive detection limit of 0.187 nM. We have innovated a portable wireless sensing system, coupled with a Janus membrane for expedited plasma separation, consolidating a portable platform dedicated to vancomycin sensing. Furthermore, we have realized the detection of vancomycin concentration in patient's blood using this sensor, and the results are reliable. This comprehensive study underscores the immense potential of multi-doped graphene EG-FET sensors in the realm of antibiotic detection, thereby contributing a pivotal tool towards the realization of precision medicine strategies.