Gold nanoparticle-enhanced secondary ion mass spectrometry imaging of peptides on self-assembled monolayers.
We demonstrate the use of gold nanoparticles (AuNPs) to enhance the secondary ion emission of peptides in time-of-flight secondary ion mass spectrometry (TOF-SIMS). The signal intensity of peptides adsorbed onto AuNPs was significantly increased when compared to that of self-assembled monolayers (SAMs). This gold nanoparticle-enhanced SIMS, termed NE-SIMS, enabled the sensitive detection of subtle modifications of peptides, such as phosphorylation. From a quantitative analysis of the amounts of adsorbed peptides and AuNPs on SAMs using quartz crystal microbalance and surface plasmon resonance spectroscopy, the ratio of peptide molecule to AuNP on amine-SAMs was revealed to be 18-19:1. When considering the ratio of peptide to matrix (1:10(3)-10(6)) employed in a matrix-enhanced SIMS, the use of AuNPs gave rise to a significantly increased secondary ion emission of peptides. Peptides were adsorbed onto patterned AuNPs on SAMs using a microfluidic system, and well-contrasted molecular ion images were obtained. NE-SIMS is expected to be applied to a chip-based analysis of modification of biomolecules in a label-free manner.
Kim
Young-Pil
YP
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1, Kusung-Dong, Yusung-Gu, Daejeon 305-701, Korea.
Oh
Eunkeu
E
Hong
Mi-Young
MY
Lee
Dohoon
D
Han
Min-Kyu
MK
Shon
Hyun Kyong
HK
Moon
Dae Won
DW
Kim
Hak-Sung
HS
Lee
Tae Geol
TG
D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000032:analysis*; D012680:Sensitivity and Specificity; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D013997:Time Factors
D008567:Membranes, Artificial; D010455:Peptides; D006046:Gold