Biological elemental analysis: A cute-meet of microfluidic device to inductively coupled plasma mass spectrometry

The elemental analysis in disease diagnosis and biomedicine screening generally aims at alleviating the difficulties of sample pretreatment techniques, elucidating the distribution and speciation information of elements in bio-samples as well as elevating resolution of multidimensional elemental profiling. The integration of microfluidic techniques with inductively coupled plasma mass spectrometry (ICP-MS) has been demonstrated to possess great potential in these aspects due to the versatile microstructure design, rapid sample pretreatment, extremely low sample consumption, and high-sensitivity/high-throughput elemental detection capability. Herein, an overview of the advancements in microfluidic-based ICP-MS for precise biological elemental determination is provided. A few microfluidic approaches for multiplex and effective manipulation of clinical samples followed by detection with ICP-MS are highlighted, that is, high spatiotemporal resolution sampling, high-purity elemental microextraction device, and high signal-to-noise ratio elemental analysis. In addition, other front-end techniques are discussed for converting various types of samples into a suitable form for detection, for example, laser ablation and time of flight MS. The opportunities and outstanding challenges of microfluidic-based ICP-MS elemental investigations in clinical diagnosis and biomedical studies are also depicted.