Methods for analyte detection with magnetic sensors are provided. Aspects of the methods include producing a magnetic sensor device having a magnetically labeled analyte from a sample, such as a serum sample, bound to a surface of a magnetic sensor thereof; and obtaining a signal, e.g., a real-time signal, from the magnetic sensor to determine whether the analyte is present in the sample. Also provided are devices, systems and kits that find use in practicing the methods of the invention. The methods, devices, systems and kits of the invention find use in a variety of different applications, including detection of biomarkers, such as disease markers.