Herein, we synthesized molybdenum oxide quantum dots using bovine serum albumin as a ligand (BSA-MoOx QDs) via a simple method. The synthesized fluorescent BSA-MoOx QDs were stable, and blue fluorescence was noticed upon exposure to UV lamp at 365 nm. When excited at 320 nm, BSA-MoOx QDs showed an emission peak at 406 nm. Atomic force microscopic images demonstrated that the thickness of BSA layer on the surface of MoOx QDs is 3.9 ± 1.6 nm. The as-synthesized BSA-MoOx QDs acted as a sensor for the detection of digoxin, La3+, and epinephrine via fluorescence OFF-ON-OFF mechanisms, exhibiting linear ranges of 1–25, 0.125–5, and 0.5–10 μM with lower detection limits of 9.74, 23.08, and 4.58 nM for digoxin, La3+, and epinephrine, respectively. This method was successfully demonstrated to be an effective analytical platform for measuring digoxin and epinephrine in pharmaceutical and biofluid samples.