Multiple electrospray device, systems and methods

A microchip-based electrospray device, system, and method of fabrication thereof are disclosed. The electrospray device includes a substrate defining a channel between an entrance orifice on an injection surface and an exit orifice on an ejection surface, a nozzle defined by a portion recessed from the ejection surface surrounding the exit orifice, and an electric field generating source for application of an electric potential to the substrate to optimize and generate an electrospray. A method and system are disclosed to generate multiple electrospray plumes from a single fluid stream that provides an ion intensity as measured by a mass spectrometer that is approximately proportional to the number of electrospray plumes formed for analytes contained within the fluid. A plurality of electrospray nozzle devices can be used in the form of an array of miniaturized nozzles for the purpose of generating multiple electrospray plumes from multiple nozzles for the same fluid stream. This invention dramatically increases the sensitivity of microchip electrospray devices compared to prior disclosed systems and methods.