## 2 Methodology
This is important because desorbing electrospray droplets are capable of pulling out polar or polarizable trace species out of the air, of which pathogens are, while ignoring the background air. The ability of electrospray to \"getter\" or collect pathogens affords a means to concentrate otherwise dilute targets in the ambient environment. Identification of pathogens such as viruses can then be accomplished based on charge-to-mass ratio using a charge detector flight tube [14]. Figure 4: Graph representing aerosol particle concentration using a laser particle counter. An electrospray source when activated captured ambient 3.0 micron bacterial simulant, reducing the overall particle concentration background signal. Figure 3: Penicillium Spores collected by electrospray in our laboratory in open air and visualized by Amscope microscopy (\(\times\)1000). Droplets vs. Discrete Viral or Bacterial Species:  
Separating viral or viral-like particles or bacteria or bacterial-like particles from an electrospray captured and charged droplet is a challenge to be addressed. As discussed earlier, electrospray produces charged droplets, that attract polar species, and can interact kinetically with ambient particles. Respiratory droplets have \"diameters that cover a large size range from approximately 0.6 to more than 1000 \(\upmu\)m\" [15]. The new-formed droplet will now carry the charges from the original electrospray droplet. In traditional electrospray mass spectrometry, the solvent species in the droplet evaporates while the droplet is in flight. This is assisted by the counter-current dry nitrogen flow between the electrospray source and the inlet capillary of the MS. The desolvation process or \"Coulomb Explosion\" continues until all solvent is removed by transitioning to the vapor phase, leaving a single intact ion. Similarly, in the proposed embodiment, a suitable solvent for the glycoproteins, proteoglycans, lipids, and other proteins contained in respiratory ejecta, can serve the same purpose in creating discrete charged species as in ESI-MS used to study organic macromolecules. One such potential solvent would be a 50:50 water-hexane mixture. Solid-liquid separation of porcine gastric mucins was successfully demonstrated to extract proteins [16]. However, the use of polar and non-polar substances together requires another trick discussed later, known as coaxial electrospray. Characterization and of Pathogens--Building a Database of Human Pathogen Features: Bacterial identification currently relies on biochemical processing, techniques that are labor intensive, require special skills, and are not real-time [17]. Optical processing of bacteria would allow for much quicker identification and a concomitant rapid response by health care professionals when dealing with an outbreak, curtailing possible exponential spread, and shortages of essential personal protective equipment. Bacterial pathogen features and characteristics were collected and a database with structural and visually identifiable patterns that have an affinity for binding oligonucleotide aptamers and enhancing visualization (described below) are listed in Table 1. Bacteria come in a plethora of different shapes and sizes. It is this variability in phenotypic structure that allows researchers to differentiate between the approximately 10,000 known bacteria. For the proof of concept described herein, the dataset is focused on visually identifiable characteristics that include the gram stain, absence or presence of capsule, shape and arrangement of bacteria, presence of flagella or pili, and the type of flagella or pili present. The intent here would be o apply artifical intelligence (AI) with image analysis for microbe characterization and possible identification. A Gram stain is used to separate between the two types of bacteria, Gram-positive and Gram-negative. The Gram-positive bacteria have a monoderm surrounded by a thick peptidoglycan layer (20-80 nm thick), and the Gram-negative bacteria have a thin peptidoglycan layer (5-10 nm thick) between diderms.