We will report results about the noise and performance of magnetic nanosensors based on niobium nano superconducting quantum interference device (nanoSQUID) having a flux capture area of 0.5 μm2. A proper device design based on a loop inductance asymmetry has been developed in order to achieve a better magnetic flux resolution. The device fabrication procedure is based on the electron-beam lithography, thin film deposition, and the lift-off technique. The characterization of the nanodevice at T =4.2 K includes measurements of current–voltage, critical current vs. magnetic flux characteristic (I−Φ), and flux noise. The nanosensors have shown a hysteretic I–V characteristic and a triangular-shaped I−Φ pattern. Due to the hysteretic behavior, the devices have been employed as a magnetic flux to current transducer. In such a configuration, an overall magnetic flux resolution of about 0.1 mΦ0 has …