These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
submitted on 03.06.2019 and posted on 04.06.2019by Ewelina P. Dutkiewicz, Han-Jung Lee, Cheng-Chih Hsu, Yu-Liang Yang
spectrometry (IMS) is
a powerful technique that enables analysis of various molecular species
at a high spatial resolution with low detection limits. In contrast to the standard matrix-assisted laser desorption/ionization mass
spectrometry (MALDI-MS) approach, surface-assisted laser desorption/ionization
(SALDI) is more effective in the detection of small molecules due to the absence
of interfering background signals in low m/z
ranges. We developed a functionalized TiO2 nanowire as a solid
substrate for IMS of low-molecular-weight species in biological specimens. We
prepared TiO2 nanowires using the inexpensive modified hydrothermal
process and subsequently functionalized it chemically with various silane
analogs to overcome the problem of superhydrophilicity of the substrate.
Chemical modification changed the selectivity of imprinting of samples
deposited on the surface of the plate and thus improved the detection limits. Due
to the enhanced performance, the functionalized TiO2 nanowire
substrate could be successfully used for imaging of complex native samples. We
applied our new substrate to image distribution of the secondary metabolites in
(1) petal of the medicinal plant Catharanthus
roseus and (2) microbial co-culture of Burkholderiacenocepacia 869T2 vs Phellinus
noxius. We observed that secondary metabolites are distributed heterogeneously
in a petal, which is consistent with previous results reported for the C. roseus plant leaf and stem. We
verified the semi-quantitative capabilities of the imprinting/imaging approach
by comparing results using standard LC-MS analysis of the plant extracts. Several
bacteria-related metabolites produced by B.
cenocepacia 869T2 in presence of P. noxius, which were unable to be detected by MALDI-MS approach,
were revealed by our newly developed approach. This suggested that the
functionalized TiO2 nanowire substrates-based SALDI is a powerful technique
complementary to MALDI-MS.