Bioinspired Colorimetric Detection of Calcium(II) Ions in Serum Using Calsequestrin‐Functionalized Gold Nanoparticles

Abstract

Seeing is sensing: Calsequestrin (CSQ) functionalized gold nanoparticles undergo calcium-dependent CSQ polymerization, which results in a clear color change (see picture) together with precipitation. The sensing system is specific for Ca(2+) ions and the differences between normal and disease-associated abnormal (hypercalcemia) Ca(2+) ion levels in serum can be distinguished with the naked eye.