Recent advancements in nanoelectrospray ionization interface and coupled devices

As a major sample introduction method, electrospray ionization has been widely used as the frontend interface for mass spectrometry due to its unique advantages, including high ionization efficiency, no sample breakage, ionization capability for polar and macromolecular samples, and ease of modification. Lowing the flow rate to the nanoelectrospray regime ( < 1000 nL/min) not only reduces sample consumption and increases sensitivity, but also tolerates high concentrations of matrix salts, which is beneficial to sensitively analyzing trace biological samples. While the nanoelectrospray performance is highly related to emitter structures, different designs and architectures of the nanoelectrospray interface also have a great impact on the operational approaches and analytical targets. In this review, we summarized and discussed recent developments in nanoelectrospray modules that have a significant impact on the performance and functionality of the nanoelectrospray ionization interface, including emitter, sample injection, and electrical contact. The mechanisms and applications of these newly-developed nanoelectrospray interfaces will also be discussed.