In the world of medicine, the discovery of acyclovir, an antiviral medication often used to treat herpes infections, is very important. Accurate and sensitive detection are essential for patient safety since acyclovir is recognized for its possible adverse effects and toxicity at high dosages. A Cu metal-organic framework (MOF) doping with Fe3O4/SiO2 was prepared by direct Co-precipitation method. This binary Fe3O4-SiO2/Cu-MOF was analysis by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD), and this MOF was used to modify the glassy carbon electrode (GCE) surface. Modified GCE was used for the electrochemical monitoring of Acyclovir in the plasma samples. Acyclovir’s electro-oxidation behavior was assessed using cyclic and differential pulse voltammetric techniques. A redox mechanism was postulated based on the effect of the potential scanning rate and solution pH on the voltammetric response of Acyclovir oxidation. A 0.03 μM limit of detection was acquired for Acyclovir analysis with a linear response in the range of 1–60 μM. Finally, acyclovir quantification in the blood serum samples was successfully performed.