Mass Spectrometric Bioanalysis Assisted by Noble Metal Nanoparticles - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 280

accomplished using commercial AgNPs as matrices. 44 Because
AgNPs do not form crystals as it dries, good reproducibility of the
mass spectral signals is achieved in AgNP-assisted LDI-MS.
Figure 12.3 MALDI time-of-light mass spectra of the 12 component
mixture obtained using (A) DHB with 120 μM AgNO 3 and
(B) 20 nm AgNPs. The [M + H] + or [M + Na] + (denoted by a
“ ∗ ”) ions of each peptide is numbered in the spectrum and
identiied in Table 12.1. A high abundance of [M + Na] + ions
(unlabeled peaks) are observed owing to the PBS buffer
used to prepare the small unilamellar vesicles. Structures
for both cholesterol and POPC are provided. Reprinted with
permission from Ref. 42.
Very recently, Yeung et al . used the same LDI matrices for the
direct proiling and imaging of epicuticular waxes on Arabidopsis
thaliana leaves and lowers. 45 Because of reproducible spraying
of AgNP solution onto the plant's surface, high spatial resolution
imaging (~100 μm) of plant surface metabolites has been obtained by
LDI-MS. Compared to gas chromatography/MS for the determination
of cuticular wax metabolite on lower organs of Arabidopsis, AgNP-
assisted LDI-MS has several advantages: (a) sample preparation