Atmospheric Pressure Mass Detection of Single Ethanol Molecules Based on Microresonator and Feedback Control

In biochemical reaction detection, nanoresonant detection technique requires ultralow temperature and ultrahigh vacuum. Microresonant detection technique could work under room temperature and atmospheric pressure, but their mass detection sensitivity is too low. In this study, a feedback control principle was employed to reduce the equivalent mass of the microresonator, thereby enhancing its mass detection sensitivity and achieving single-molecule mass detection precision. Tuning the feedback gain, the sensitivity of the microresonant detection technique was increased by 1.01×10
¹³
times, reaching 3118.16 Hz/zg. The detection sensitivity reached the level of single ethanol molecule (weighing 0.076 zg). Using the method, the adsorption and desorption of ethanol molecules at the microresonator end was successfully detected at room temperature and atmospheric pressure. The method could be used in biochemical reaction detection of single molecular detection accuracy.