Recent developments of nanoparticle-based enrichment methods for mass spectrometric analysis in proteomics

In proteome research, rapid and effective separation strategies are essential for successful protein identification due to the broad dynamic range of proteins in biological samples. Some important proteins are often expressed in ultra low abundance, thus making the pre-concentration procedure before mass spectrometric analysis prerequisite. The main purpose of enrichment is to isolate target molecules from complex mixtures to reduce sample complexity and facilitate the subsequent analyzing steps. The introduction of nanoparticles into this field has accelerated the development of enrichment methods. In this review, we mainly focus on recent developments of using different nanomaterials for pre-concentration of low-abundance peptides/proteins, including those containing post-translational modifications, such as phosphorylation and glycosylation, prior to mass spectrometric analysis.