Application and development of superparamagnetic nanoparticles in sample pretreatment and immunochromatographic assay

Superparamagnetic nanoparticles (SMNPs) have been widely used in immunochromatographic assay (ICA) platform and achieved outstanding effects for overcoming the disadvantages of low sensitivity and poor matrix tolerance of ICA. The review presents the improvement of sensitivity and matrix tolerance of ICA due to immunomagnetic separation (IMS). Moreover, some novel magnetic separation technology, developed as new alternatives to IMS, based on non-antibody reagents are displayed to illustrate the novel concepts in various applications. SMNPs also act as a novel label for the signal output of ICA (SMNPs-ICA). This part focuses on examples of SMNPs-ICA based on optical and magnetic signal read modes to illustrate the advantage of SMNPs-ICA. At the same time, novel concepts in various sensors for magnetic reading and used as potential applications for screening tools are introduced. We also highlight the superiority of SMNPs aggregation-based, enzyme or nanozyme-based, and external magnetic field-based strategies for SMNPs-ICA. (C) 2019 Elsevier B.V. All rights reserved.