Core-satellite gold nanoparticle biosensors for monitoring cobalt ions in biological samples

Elevated cobalt levels in the bloodstream due to wear debris from metal-on-metal hip implants can cause adverse health effects. Herein, we report a highly sensitive and specific label-free assay for cobalt detection using cysteine-linked core-satellite gold nanoparticles. We demonstrate the detection of clinically relevant concentrations of cobalt ions in biological samples down to 10 nM within 15 minutes using a standard laboratory plate reader. This method can be developed as a valuable tool for prompt monitoring of cobalt ion levels in patients with metal-on-metal hip implants.