A sample preparation method for gold nanoparticle-assisted laser desorption/ionization time-of-flight mass...

A sample preparation method to detect small molecules in laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) was developed using bare gold nanoparticles (AuNPs) as matrices. In this sample preparation method, the analyte is deposited first and then followed by the bare AuNPs. Neutral steroids and carbohydrates, which are difficult to ionize, using organic matrices, are cationized efficiently by combining AuNP-assisted LDI-TOF MS with this sample preparation method. As compared to the dried-droplet method (i.e., analyte and bare AuNPs are mixed and dried together), this method offers distinct advantages for improving shot-to-shot reproducibility, increasing the ionization efficiency of the analyte, and reducing sample preparation time.