The core requirements for point-of-care (POC) diagnostics necessitate low-cost, high multiplexing, portability, easily integrated sample preparation, and quick measurement time. Frequency-shift based magnetic sensing is a measurement technique utilizing a complementary metal-oxide-semiconductor (CMOS) integrated-circuit (IC) chip for magnetic label detection. Using this technology, we have developed a complete handheld, low-power, low-cost, disposable cartridge-based diagnostic device with two fully implemented assays for antigens and nucleic acids. We have demonstrated reliable measurements down to 100 pM for a 31 base-pair oligomer and 1 pM for the protein interferon-γ (IFN- γ).