16-Mer ferritin-like protein templated gold nanoclusters for bioimaging detection of methylmercury in the brain of living mice.

Methylmercury (MeHg+) as one of the most potent neurotoxins is mainly accumulated in brain, so in vivo imaging detection of MeHg+ in brain is of crucial importance. Herein, we reported a photoluminescent nanosensor for MeHg+ detection in brain by integrating the bioimaging of gold nanoclusters (Au NCs), the fluorescence of Au NCs quenched by MeHg+, and the brain targeting feature of our recently constructed 16-mer shell-like protein (7A). First, Au NCs with 7A as a biotemplate (7A-Au NCs) by a facile and green method in water are fabricated for the first time, the fluorescence of which (∼650 nm) can be quenched by MeHg+ in a dose-dependent manner in vitro. Second, the as-prepared 7A-Au NCs are not only suitable for bioimaging of BBB endothelial cells, but also are an effective probe for bioimaging MeHg+ detection in a brain-specific manner. These findings open a door for MeHg+ detection in the brain of living subjects. 16-Mer ferritin-like protein templated gold nanoclusters (Au NCs) were fabricated for bioimaging detection of MeHg+ in the brain of living mice by taking advantage of the ability to traverse blood brain barrier, and the bioimaging of Au NCs, the fluorescence of Au NCs quenched by MeHg+. Image 1 • A novel 16-mer ferritin-like protein, 7A, has the ability to pass through blood brain barrier as human H chain ferritin does. • 7A molecules were utilized as biotemplates to fabricate highly fluorescent Au NCs. • 7A biotemplated Au NCs act as biosensors for bioimaging detection of MeHg+ in the brain of living mice. [ABSTRACT FROM AUTHOR]