Advances in LDI-MS\nAnalysis: The Role of Chemical\nVapor Deposition-Synthesized Silver Nanoparticles in Enhancing Detection\nof Low-Molecular-Weight Biomolecules

In\nthis investigation, we detail the synthesis of silver\nnanoparticles\n(AgNPs) via a precise chemical vacuum deposition (CVD) methodology,\naimed at augmenting the analytical performance of laser desorption/ionization\nmass spectrometry (LDI-MS) for the detection of low-molecular-weight\nanalytes. Employing a precursor supply rate of 0.0014 mg/s facilitated\nthe formation of uniformly dispersed AgNPs, characterized by SEM and\nAFM to have an average diameter of 33.5 ± 1.5 nm and a surface\nroughness (<i>R</i><sub>a</sub>) of 11.8 nm, indicative\nof their homogeneous coverage and spherical morphology. XPS and SEM-EDX\nanalyses confirmed the metallic silver composition of the nanoparticles\nwith Ag peak splitting, reflecting the successful synthesis of metallic\nAg. Comparative analytical evaluation with traditional MALDI matrices\nrevealed that AgNPs significantly reduce signal suppression, thereby\nenhancing the sensitivity and specificity of LDI-MS for low-molecular-weight\ncompounds such as triglycerides, saccharides, amino acids, and carboxylic\nacids. Notably, the application of AgNPs demonstrated a superior linear\nresponse for triglyceride signals with regression coefficients surpassing\n0.99, markedly outperforming conventional matrices. The study further\nextends into quantitative analysis through nanoparticle-based laser\ndesorption/ionization (NALDI), where AgNPs exhibited enhanced ionization\nefficiency, characterized by substantially lower limits of detection\n(LOD) and quantification (LOQ) for tested standards. Particular attention\nwas paid to lipids with a detailed examination of their fragmentation\npathways. These results highlight the significant potential of AgNPs\nsynthesized via CVD to transform the analytical detection and quantification\nof low-molecular-weight compounds using NALDI. This approach offers\na promising avenue for expanding the scope of analytical applications\nin mass spectrometry and introducing innovative methodologies for\nenhanced precision and sensitivity.