Development of a low-cost complex AC susceptometer for the analysis of nanoparticles in biological systems

• Grant number: 25/12871-3
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2025
• End date: September 30, 2027
• Field of knowledge: Biological Sciences - Biophysics - Biophysics of Processes and Systems
• Principal Investigator: Guilherme Augusto Soares
• Grantee: Guilherme Augusto Soares
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

This project proposes the development and enhancement of an Alternating Current Biosusceptometry (BAC) system capable of measuring the complex magnetic susceptibility of magnetic nanoparticles (MNPs), including both real and imaginary components. Unlike high-cost commercial equipment such as DynoMag, the BAC system is portable, affordable, and feasible for implementation in mid-scale laboratories, especially within the Brazilian research context. However, its current application is limited to the detection of the real component of susceptibility, restricting the analysis of dynamic mechanisms such as Brownian relaxation.The proposal aims to adapt the BAC system for broader frequency sweeps by incorporating a radiofrequency amplifier and calibrating the setup using paramagnetic standards (Dy¿O¿). The methodology involves both in vitro and in vivo experiments to investigate how different surface coatings - with or without the formation of a protein corona - affect the magnetic properties and cellular uptake of MNPs. Human epithelial cell models (HaCaT and Caco-2) and proteomic analyses (LC-MS/MS) will be used to characterize the protein corona composition and its role in the biological behavior of nanoparticles.The project seeks to offer a technically and economically viable alternative for magnetic characterization of MNPs, with direct impact on biosensing, diagnostics, and the development of nanoparticle-based therapies. As such, it is expected to advance national scientific and technological capacity in nanomedicine, reduce dependency on imported systems, and foster the training of highly qualified human resources. (AU)