Use of flower-like gold nanoparticles in time-of-flight mass spectrometry
|Year of publication
|Article in Periodical
|Magazine / Source
|Rapid Communication in Mass Spectrometry
|MU Faculty or unit
|Flower-like gold nanoparticles; MALDI; SALDI; TOF mass spectrometry; biomolecules
|Many kinds of nanoparticles (NPs) have been used for mass spectrometry (MS) so far. Here we report the first use of flower-like gold nanoparticles (AuNPs) as a mediator enhancing ionization in MS of peptides and proteins. Flower-like AuNPs were characterized using transmission and scanning electron microscopy, UV-VIS spectrophotometry, and laser desorption/ionization (LDI) MS and compared with polyhedral AuNPs. Mass spectra were obtained in positive ion mode using time-of-flight (TOF) analyzer coupled with either matrix assisted laser desorption/ionization (MALDI) or surface assisted laser desorption/ionization (SALDI) methods. The intensities of peptide peaks (m/z 500–3500) were up to 7.5× and up to 7× higher using flower-like AuNPs and flower-like AuNPs-enriched cyano-4-hydroxycinnamic acid (CHCA) matrix respectively, than the classical CHCA matrix. The signals of higher mass peptide/protein peaks (m/z 3600–17000) were up to 2× higher with using flower-like AuNPs enriched CHCA matrix than conventional CHCA matrix. The signal of profile peaks generated by intact cell MALDI-TOFMS of fibroblast suspension (m/z 4000–20000) was 2× higher with using flower-like AuNPs combined with sinapinic acid (SA) compared to SA matrix alone. The use of flower-like AuNPs as internal calibration standard for the calibration of MS spectra of peptides was performed. Flower-like AuNPs and flower-like AuNPs combined with CHCA or SA as combined matrices for MS measurement of peptides and proteins were used. Comparison of conventional MALDI method and our method with flower-like AuNPs was carried out. In addition, gold clusters generated from flower-like AuNPs by SALDI provide suitable internal calibration standard for MS analysis of peptides.