Magnetic nanoparticles (MNPs) have emerged as promising materials for advanced biomedical biosensing because of their distinctive magnetic properties, high surface-to-volume ratio, and ability to interact selectively with biological targets. This study proposes the development of a magnetic nanoparticle-based biosensing system for rapid and sensitive detection of biomolecular targets in biomedical samples. The proposed approach investigates the interaction of functionalized MNPs with target biological agents and utilizes their magnetic response for quantitative detection. A magneto-resistive, particularly Giant Magnetoresistance (GMR)-based, sensing platform is considered for measuring changes in magnetic field generated by the concentration and distribution of MNPs associated with target analytes. The research focuses on the design and optimization of the sensing architecture, signal-conditioning and processing circuits, nanoparticle functionalization, and quantitative analysis of sensor responses. Important performance parameters, including sensitivity, selectivity, limit of detection, response time, repeatability, and measurement accuracy, will be evaluated under controlled experimental conditions. The proposed system aims to provide a compact, rapid, reliable, and potentially low-cost alternative to conventional laboratory-based detection techniques. The study further investigates the influence of nanoparticle size, concentration, surface modification, and magnetic properties on biosensor performance. The expected outcome is an integrated nanoparticle-based magnetic biosensing platform capable of detecting and quantifying selected biological or biomolecular agents in liquid samples. Such a system could contribute to the development of portable point-of-care diagnostic technologies and facilitate rapid biomedical screening. The research is expected to strengthen the application of nanotechnology, magneto resistive sensing, and signal processing in next-generation biomedical diagnostics.