The electrical resistance of a metallic structure with several nanometers non-magnetic conducting thin film (e.g. copper) sandwiched between two ferromagnetic layers changes depending on the relative magnetization direction of the ferromagnetic layers. One ferromagnetic layer is held fixed while the other is free to respond to an external magnetic field.

Parallel magnetization results in lower resistance, while anti-parallel magnetization results in higher resistance. This phenomenon facilitates detection of stray fields from magnetic materials at nanometer scales.

A bead with magnetic nanoparticles tethered to the sensor through analytes in a biological assay changes the magnetic field acting on the field-sensitive ferromagnetic layer in the GMR structure, which can be detected as a small change in resistance.

Zepto Life’s on-chip bio-surface technology anchors assay-specific capture molecules in place. The bio-surface on the nanomagnetic beads binds them to assay-specific detection molecules so that nanomagnetic beads are tethered to the sensor surface as a consequence of the assay. In a prototypical immunoassay, the nanomagnetic beads sit atop a sandwich created by specific binding of analyte biomarkers between capture and detection antibodies. The accumulation of nanomagnetic beads tethered to the sensor surface produces a signal that is read out real-time. Each biosensor in the array is dedicated to a single biomarker.

The multiple biosensors on a biochip is designed to deliver clinical results of a central laboratory at a point of care (POC) setting.
Each biochip is able to simultaneously detect and quantify multiple biomarkers.

Zepto life technology leverages the precise flow rate control of microfluidics technology with our proprietary GMR sensor for an automated, effective, and repeatable test. This technology is cost-effective and requires only a minimal amount of patient samples. Zepto’s engineering and design philosophy of focusing on minimizing patient and user input lay the groundwork for robust assays in compact platforms suitable for point-of-care testing.