Browsing by Author "Lin, Hong-Yi"

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Detection of phosphopeptides by localized surface plasma resonance of titania-coated gold nanoparticles immobilized on glass substrates
(2006-10-01)
Lin, Hong-Yi
;
Chen, g-Tai Chen
;
Chen, Yu-Chie
;
應用化學系
;
應用化學系分子科學碩博班
We herein demonstrate a new sensing method for phosphopeptides by localized surface plasmon resonance (LSPR) using titania-coated gold nanoparticles immobilized on the surface of a glass slide as the sensing substrate and using UV-visible spectrophotometry as the detection tool. Titania has been known to be an effective substrate for binding with phosphorylated species. The detection principle is the shift of wavelength of optical absorption due to SPR of the gold nanoparticles induced by binding of phosphorylated species with titania on the surface of the gold nanoparticles. The feasibility of the approach is demonstrated by detection of tryptic digest products of beta-casein and milk. Gold nanoparticles coated with thin films of titania, immobilized on a glass slide, can selectively bind traces of phosphopeptides from complex samples, resulting in a wavelength shift of the absorption band in the SPR spectrum with good reproducibility. The LSPR results are confirmed by matrix-assisted laser desorption/ionization mass spectrometry. The detection limit for the tryptic digest product of beta-casein is 50 nM.
Iron Oxide/Niobium Oxide Core-Shell Magnetic Nanoparticle-Based Phosphopeptide Enrichment from Biological Samples for MALDI MS Analysis
(2009-04-01)
Lin, Hong-Yi
;
Chen, Wei-Yu
;
Chen, Yu-Chie
;
應用化學系
;
Department of Applied Chemistry
The feasibility of using niobium oxide-coated magnetic nanoparticles (NPs) as affinity probes for selectively trapping phosphopeptides from peptide mixtures including tryptic digest of caseins, serum, and cell lysate was demonstrated in this study. Phosphopeptide enrichment was rapid when subjecting these systems to microwave heating for 1 min; the probe-target species, which were readily isolated through magnetic separation, were then analyzed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Only signals for phosphopeptides were present in the resulting mass spectra. The detection limit for monophosphopeptide was as low as 5 fmol.
Iron oxide/tantalum oxide core-shell magnetic nanoparticle-based microwave-assisted extraction for phosphopeptide enrichment from complex samples for MALDI MS analysis
(2009-08-01)
Lin, Hong-Yi
;
Chen, Wei-Yu
;
Chen, Yu-Chie
;
應用化學系
;
Department of Applied Chemistry
A new type of metal-oxide-coated magnetic nanoparticles (NPs)-tantalum-oxide-coated magnetic iron oxide (Fe(3)O(4)@Ta(2)O(5)) NPs-which are used as affinity probes for selectively trapping phosphopeptides from complex samples, is demonstrated in this study. In this approach, phosphopeptide enrichment was achieved by incubating the NPs with sample solutions under microwave heating within 1 min. The NP-target species conjugates were readily isolated from samples by magnetic separation followed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analysis. When using human serum as the sample, phosphorylated fibrinopeptide-A-derived ions are the only ions observed in the MALDI mass spectra after enrichment by the Fe(3)O(4)@Ta(2)O(5) NPs. Furthermore, only phosphopeptides appear in the MALDI mass spectra after using the affinity probes to selectively trap target species from the tryptic digest of a cell lysate and milk sample. The results demonstrated that the Fe(3)O(4)@Ta(2)O(5) NPs have the capability of selectively trapping phosphorylated peptides from complex samples. The detection limit of this approach for a phosphopeptide (FQpSEEQQQTEDELQDK) was similar to 10 fmol.