Nanoparticles as labels of specific-recognition reactions for the determination of biomolecules by inductively coupled plasma-mass spectrometry.

Inductively coupled plasma - mass spectrometry (ICP-MS) is an essential tool for quantitative ultratrace elemental and isotopic determinations in the biological and biomedical fields. In addition, sensitive and multiplexed quantification of target biomolecules in biological fluids and single-cells by ICP-MS can be carried out using metal elements or their isotopes as labels of immunoreaction and hybridization specific-recognition reactions. Following similar strategies, the bioimaging of biomolecules in tissues and single-cells by laser ablation (LA)-ICP-MS can be also achieved. Sensitivity can be further increased by resorting to amplification strategies based on the use of labels containing several atoms of a given elemental (or isotopic) reporter, such as inorganic nanoparticles (NPs). In this review, we intend to highlight the progress achieved in this active research area. Following the introduction, a short report of the characteristics of the most relevant NPs used as labels of specific-recognition reactions for ICP-MS detection, as well as the most common labelling routes are given. Then, the applications of NPs-labelled detection probes used in combination with ICP-MS (either with liquid nebulization or LA sampling) for identification and determination of proteins and oligonucleotides in biological samples are thoroughly reviewed. In the conclusions section, the challenges faced and the expected advances in this topic are underlined.