Detection of proteins and protein--ligand complexes using HgTe nanostructure matrixes in surface-assisted laser desorption/ionization mass spectrometry

We have analyzed peptides, proteins, and protein--drug complexes through surface-assisted laser desorption/ ionization mass spectrometry (SALDI-MS) using HgTe nanostructures as matrixes. We investigated the effects of several parameters, including the concentration of the HgTe nanostructures, the pH of the buffer, and the concentration of salt, on the performance of this system. When HgTe nanostructures are used as matrixes, [[M + H].sup.+] ions were the dominant signals. Relative to other commonly used nanomaterials, HgTe nanostructures provided lower background signals from metal clusters, fewer fragment ions, less interference from alkali-adducted analyte ions, and a higher mass range (up to 150 000 Da). The present approach provides limits of detection for angiotensin I and bovine serum albumin of 200 pM and 14 nM, respectively, with great reproducibility (RSD: 10.1021/ac100550c