MoS₂ Nanoparticles as Electrocatalytic Labels in Magneto-Immunoassays

Ability to detect biomolecules with a simple and cost-effective approach has been very demanding in today's medicine. The nanoparticles and two-dimensional materials have been extensively used within this field in devices with high selectivity and sensitivity. Here, we report the use of MoS₂ nanoparticles (MoS₂ NPs) as a signal-enhancing label in a standard immunoassay test. MoS₂ NPs were prepared by a bipolar electrochemistry method. The current response during the hydrogen evolution reaction catalyzed by MoS₂ was measured. This current was directly proportional to the amount of the MoS₂ NPs and thus also to the concentration of desired protein. The immunoassay containing the MoS₂ NPs displays extraordinary low limit of detection (1.94 pg mL^-1), good selectivity, and reproducibility. This MoS₂ NP detection system could have profound implication for analytical applications.