Computational modeling and characterization methods for rotating magnetic nanochain-enhanced lateral flow...

This article provides comprehensive methodological guidance for implementing rotating magnetic nanochain-enhanced lateral flow immunoassays with volumetric magnetic detection. Rotating magnetic nanochains act as microscale stirrers that substantially enhance antibody-antigen binding kinetics through convective mixing, yet their integration into lateral flow platforms presents unique technical challenges requiring both computational optimization and specialized characterization. We describe complete workflows for: (i) computational fluid dynamics modeling using COMSOL Multiphysics to simulate nanochain rotation, fluid flow, and mass transport enhancement; (ii) electron microscopy characterization of magnetic nanochain morphology and size distributions; (iii) rotating magnetic field generator design and operation; and (iv) magnetic particle quantification measurement procedures for volumetric signal readout. Each section provides step-by-step instructions with sufficient detail to enable independent replication. The described methods enable development of lateral flow assays achieving sub-nanogram detection limits with rapid (6-minute) analysis times, addressing critical needs in point-of-care diagnostics. These methods complement our related research article in Biosensors and Bioelectronics by providing the technical foundation necessary for adoption and adaptation of this technology by other laboratories.•COMSOL Multiphysics workflow for modeling convective enhancement by rotating magnetic nanochains•Electron microscopy procedures for comprehensive nanochain characterization•Instrumentation methods for rotating field generation and volumetric magnetic particle quantification.