From Rational Design To Probe Optimization: The Role Of Nanoparticle Valency In Single Cancer Cell Detection In Blood Via Magnetic Relaxation

The conjugation of targeting ligands to iron oxide nanoparticles has achieved the development of specific assays for the detection of biomedical targets through magnetic relaxation. However, limited studies investigated how the nanoparticle valency modulates the detection response and the assays\u27 sensitivity. Through nanoparticle valency grafting, we were able to achieve single cancer cell detection in blood, with a small-molecule-carrying multivalent nanoparticle in just 15 minutes. Although exhibiting a similar diagnostic trend, a corresponding high-valency antibody-carrying nanosensor did not achieve the same detection threshold, indicating that small molecules might be attractive probes for cancer diagnostics. Overall, these studies indicate that nanoparticle multivalency is a critical parameter in the design of robust and sensitive nanoprobes for diverse clinical and field-based applications