Ultrathin calcinated films on a gold surface for highly effective laser desorption/ ionization of biomolecules

Abstract

A nanoscale calcinated silicate film fabricated on a gold substrate for highly effective, matrix-free laser desorption ionization mass spectrometry (LDI-MS) analysis of biomolecules. The calcinated film is prepared by a layer-by-layer (LbL) deposition / calcination process wherein the thickness of the silicate layer and its surface properties are precisely controlled. The film exhibits outstanding efficiency in LDI-MS with extremely low background noise in the low-mass region, allowing for effective analysis of low mass weight samples and detection of large biomolecules including amino acids, peptides and proteins. Additional advantages for the calcinated film include ease of preparation and modification, high reproducibility, low cost and excellent reusability.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 345,903, filed May 18, 2010, which is incorporated herein by reference in its entirety.GOVERNMENT INTEREST[0002]This invention was made with Government support under Grant No. CHE-0719224 awarded by the National Science Foundation (NSF). The Government has certain rights to this invention.FIELD OF THE INVENTION[0003]This invention relates to a method and system for enhanced laser desorption ionization mass spectrometric (LDI-MS) analysis of biomolecules, and more particularly to an ultrathin calcinated silicate film fabricated on a gold substrate by using a Layer-by-Layer (LbL) deposition / calcination process.BACKGROUND OF THE INVENTION[0004]The development of soft ionization techniques such as matrix assisted laser desorption ionization (MALDI) has greatly changed the field of mass spectrometric analysis. MALDI-MS benefits from its salt tolerance, si...

AI Technical Summary

Benefits of technology

The patent text describes a new type of film that has a nanocrystalline structure and low heat conductivity. This film can be made by depositing layers of poly(allylamine hydrochloride) and sodium silicate on a metal layer. The process involves alternating the deposition of these layers and calcinating them to form the calcinated silicate film. This film has potential applications in various fields such as electronics, sensors, and optics. The patent text also describes a method for making the calcinated silicate film and the use of stainless steel or glass substrates.

Problems solved by technology

This limitation has hampered its wide application in important research fields such as drug discovery and biotechnology, where small molecule detection and identification is of utmost significance.

These materials show promising results but also exhibit limitations and have suffered from problems such as inhomogeneous deposition, molecular degradation and interference from metal cluster ions.

Yet DIOS-MS has limited upper mass range, and the surface is susceptible to oxidation deactivation and requires stringent control of surface physical properties, which must be realized through careful selection of the silicon type and etching conditions, whereas nonuniform surface structures can substantially deteriorate the performance.

As a result, the thickness of these layers is in the range of 500-1000 μm and the uniformity is difficult to control.

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