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

Unlabelled: 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 (~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 new applications of SiO2@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.