【摘要】 针对微悬臂梁动态检测方式无法应用于液体环境,提出了一种利用微悬臂梁的高次谐振进行微小质量检测的方法。对于相同的被测量质量变化量,微悬臂梁的谐振级次越高,其频率偏移就越大,从而达到较高的灵敏度。以表面修饰了三乙基氢硫基十二基铵层(敏感层)的微悬臂梁为传感元件,以CrO42-为被测物,在原子力显微镜(AFM)上检测了敏感层吸附CrO24-前后微悬臂梁的5次、6次、7次和8次谐振频率的变化。结果证明,谐振级次越高,灵敏度越高,在8次谐振时的检测灵敏度能够达到2.50Hz/pg。更多还原

【Abstract】 A microcantilever working on dynamic mode is usually used for ultra-small mass detection by measuring its resonation frequency shift before and after mass adsorption.However,when operating in liquid,the heavy hydrodynamic damping effect often disables the application of a microcantilever resonating at its fundamental frequency because of its very low detection sensitivity.To solve this problem,a detection method of using higher harmonics of a microcantilever is suggested and described in this paper.For the same amount of mass change,the higher the harmonics is,the bigger the frequency shift of the microcantilever vibration will be.Experiments with CrO2-4 as target molecules,and triethyl-12-mercaptododecylammonium immobilized on a microcantilver as the detection probe,were conducted on an atomic force microscope(AFM).The results showed that higher harmonics give higher detection sensitivity,and at the 8th harmonic,a detection sensitivity of 2.50 Hz/pg was achieved.更多还原