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 SiO 2 @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, SiO 2 @Au nanoshells can achieve low detection-of-limits (~ pmol–fmol) in mass spectrometry and selective laser desorption/ionization in bio-mixtures towards diverse small molecules. By further surface modification with aptamers, Apt-SiO 2 @Au nanoshells allowed simultaneously targeted enrichment and detection of kanamycin with a detection limit at 200 pM. Our work not only starts new applications of SiO 2 @Au nanoshells in mass 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. [ABSTRACT FROM AUTHOR]