Abstract: The present invention provides variable mass labeling reagents, a set of the variable mass labeling reagents, and a multiplexed set of variable mass labeling reagents.

Abstract: The present invention provides a compound that can utilize hydrogen isotope and, at the same time, can quantify multiplexed samples at one time, as well as decreasing the cost for synthesis of the labeling agent. In addition, the present invention provides a novel method for quantitatively analyzing protein and peptide analytes having different quantities form each other using the labeling agent, wherein y-type fragment ions having a high mass which comprises the analyte remained after coupling the labeling agent with the analyte and then removing a part of the labeling agent through tandem mass spectrometry are utilized to conduct the quantitative analysis.

Abstract: Disclosed is a method of etching semiconductor nanocrystals, which includes dissolving semiconductor nanocrystals in a halogenated solvent containing phosphine so that anisotropic etching of the surface of semiconductor nanocrystals is induced or adding a primary amine to a halogenated solvent containing phosphine and photoexciting semiconductor nanocrystals thus inducing isotropic etching of the surface of the nanocrystals, thereby reproducibly controlling properties of semiconductor nanocrystals including absorption wavelength, emission wavelength, emission intensity, average size, size distribution, shape, and surface state.

Abstract: The present invention provides a compound that can utilize hydrogen isotope and, at the same time, can quantify multiplexed samples at one time, as well as decreasing the cost for synthesis of the labeling agent. In addition, the present invention provides a novel method for quantitatively analyzing protein and peptide analytes having different quantities form each other using the labeling agent, wherein y-type fragment ions having a high mass which comprises the analyte remained after coupling the labeling agent with the analyte and then removing a part of the labeling agent through tandem mass spectrometry are utilized to conduct the quantitative analysis.

Abstract: Disclosed is a method of etching semiconductor nanocrystals, which includes dissolving semiconductor nanocrystals in a halogenated solvent containing phosphine so that anisotropic etching of the surface of semiconductor nanocrystals is induced or adding a primary amine to a halogenated solvent containing phosphine and photoexciting semiconductor nanocrystals thus inducing isotropic etching of the surface of the nanocrystals, thereby reproducibly controlling properties of semiconductor nanocrystals including absorption wavelength, emission wavelength, emission intensity, average size, size distribution, shape, and surface state.

Abstract: A nanoparticle having a core/shell structure can be rapidly and reproducibly prepared by the inventive method which comprises: (i) dissolving a shell precursor in a solvent to form a shell precursor solution, and then allowing the shell precursor solution to be stabilized at a temperature suitable for the shell precursor to form an overcoat on the surface of a core nanoparticle; and (ii) adding a powder form of the core nanoparticle to the stabilized shell precursor solution.

Abstract: The present invention provides variable mass labeling reagents, a set of the variable mass labeling reagents, and a multiplexed set of variable mass labeling reagents.

Abstract: The present invention relates to a method of peptide sequencing by MALDI (matrix-assisted laser desorption ionization) tandem mass spectrometry, which comprises the steps of chemically modifying a sample peptide with at least one chemical modification method selected from the group consisting of guanidination and esterification in order to change the ionization status of the peptide and performing mass spectrometry using a MALDI tandem mass spectrometer and programmed MALDI tandem mass spectrometry. The peptide sequencing method of the present invention is advantageous in that detection sensitivity of the peptide improves significantly and various daughter ions are detected uniformly, thereby enabling perfect de novo sequencing with tandem mass spectrometry only, without database search.

Abstract: A nanoparticle having a core/shell structure can be rapidly and reproducibly prepared by the inventive method which comprises: (i) dissolving a shell precursor in a solvent to form a shell precursor solution, and then allowing the shell precursor solution to be stabilized at a temperature suitable for the shell precursor to form an overcoat on the surface of a core nanoparticle; and (ii) adding a powder form of the core nanoparticle to the stabilized shell precursor solution.

Abstract: The present invention relates to a method of peptide sequencing by MALDI (matrix-assisted laser desorption ionization) tandem mass spectrometry, which comprises the steps of chemically modifying a sample peptide with at least one chemical modification method selected from the group consisting of guanidination and esterification in order to change the ionization status of the peptide and performing mass spectrometry using a MALDI tandem mass spectrometer and programmed MALDI tandem mass spectrometry. The peptide sequencing method of the present invention is advantageous in that detection sensitivity of the peptide improves significantly and various daughter ions are detected uniformly, thereby enabling perfect de novo sequencing with tandem mass spectrometry only, without database search.