Designer SiO2@Au nanoshells towards sensitive and selective detection of small molecules in laser desorption ionization mass spectrometry

We report a novel platform using optimized SiO2@Au core-shell structures as matrices for highly efficient laser desorption/ionization mass spectrometry analysis of small biomolecules (MW < 700 Da). Owing to the designer structure, SiO2@Au nanoshells can achieve low detection-of-limits (similar to pmol-fmol) in mass spectrometry and selective laser desorption/ionization in bio-mixtures towards diverse small molecules. By further surface modification with aptamers, Apt-SiO2@Au nanoshells allowed simultaneously targeted enrichment and detection of kanamycin with a detection limit at 200 pM. Our work not only starts newapplications of SiO2@Au nanoshells inmass spectrometry, but also contributes to advanced analysis of either a group of small molecules or one target small molecule from complex bio-samples in a pre-designed manner for bio-diagnostics. From the Clinical Editor: Existing methods for the detection of small molecules are often not sensitive enough. Here, the authors developed aptamer functionalized SiO2@Au nanoshells for use in mass spectrometry, with very low detection limits. The new platform appeared to be simple and efficient and should be applicable in detection of clinical samples. (C) 2015 Elsevier Inc. All rights reserved.