Adaptive Time-Resolved Mass Spectrometry with Nanomechanical Resonant Sensors

Abstract: Nanomechanical resonant sensors that are based on detecting and tracking the resonance frequency deviations due to events of interest are being advocated for a variety of applications. All sensor schemes currently in use are subject to a basic trade-off between accuracy and speed, while there is great interest in improving both in order to enable unprecedented and widespread applications. Based on a thorough understanding of the characteristics of current resonant sensor architectures, we propose adaptive and flexible sensor schemes. Unlike recently proposed time-resolved mechanical detection methods, the proposed schemes do not require ensemble averaging of the resonator response for many independent identical stimuli. Distinct one-time events can be detected in real-time with high time resolution with an accuracy that then improves considerably with elapsed time. While the proposed adaptive schemes also need to abide by the fundamental speed versus accuracy trade-off, we show that there is still "some room at the bottom" for improvement with sensor architecture innovations. Pareto optimal performance that reaches a bound that is imposed by the fundamental thermomechanical noise can be achieved.