"Progress in a wide range of disciplines relies on the development of novel instrumentation. Pushing the limits of analytical equipment results in benefits, for example, through the discovery of illness biomarkers. This project is framed in the field of instrumentation development, in particular for the detection of vapors in real time, and with high sensitivity. Here, we propose to join the expertise of an engineering SME (SEADM) and the Swiss Federal Institute of Technology (ETH) to address four main S&T developments:i) Delivery of pre-marketable ionization sources that ultimately will be commercialized as an add-on for pre-existing mass spectrometers (MS). This will represent a cost-effective option for researchers willing to transform their MS systems into efficient detectors of vapors. During this developmental program, we will gain insights into the ionization mechanism of secondary electrospray ionization (SESI), which is the technique at the core of the add-ons to be delivered; ii) SEADM has recently proposed (patented) a SESI source capable of detecting minute gas-samples (parts per quadrillion in the gas phase, equivalent to a few femtograms). We will develop improved SESI ionizers, will couple them to various MS systems, and will use one MS available at ETH to investigate its potential in the analysis of single cell metabolomics; SEADM has developed an ion mobility spectrometer (dubbed DMA), which can be readily interfaced with pre-existing MS instruments. iii)Based on this precedent, a third instrumental development will be a SESI-DMA-MS system iv) suitable for the rapid screening of volatiles in ambient air. Such a platform would complement current commercial alternatives. This plan will be accomplished through the bidirectional exchange of knowledge. As a result, SEADM will ultimately strengthen its position in the market. The ETH will benefit by having access to novel state-of-the-art instrumentation."