Lysine detection and quantification by laser desorption/ionization mass spectrometry on gold nanoparticle-enhanced target

Abstract

Laser desorption/ionization mass spectrometry method on gold nanoparticle enhanced target (AuNPET) was used for rapid detection and quantification of lysine. The amino acid was tested directly in the concentration range from 100 μg mL⁻¹ to 1 ng mL⁻¹, which corresponds to lysine mass of 50 ng to 500 fg per analyzed spot. Detection limit value of 0.2 ng mL⁻¹ or 100 fg per spot is one of the best among the techniques used to determine lysine. In addition, mass spectrometry imaging quantification approach shown in this study canceled out sweet spot effect on the measurement result.