采用动电方法的生物细胞介电特性研究

Dielectric Property Investigation for Biological Cells with Electrokinetic Method

采用软胶粒动电理论并结合悬浮细胞单元的双电层模型,研究了在超声作用下细胞悬液的振动电位模型,并分别给出了离子和细胞动电极化电位的数学表达式及其之间的关系.根据模型建立了基于阶跃超声信号的细胞悬液动电测试系统.通过对NaCl溶液的振动电位测量表明,在低浓度离子溶液中,离子振动电位与离子浓度成正比,当离子浓度升高到一定值后,离子振动电位随离子浓度的升高呈波浪形下降,并由于超声凝聚颗粒的动电极化作用,会反相增加.通过对鸡血细胞悬液的振动电位测量表明,在低浓度细胞悬液中,由于离子与细胞动电极化的相互影响,悬液的振动电位随细胞浓度的增加而减小,当细胞浓度升高到6×105mL-1时,随着细胞浓度的升高,悬液的振动电位开始升高,此后鸡血细胞的动电极化对悬液振动电位的升高起到主要作用,从转折后的动电曲线的斜率可以实现对细胞介电特性的研究.

Following the electrokinetic theory of soft particle and the double-layer model of suspended cell unit, the colloid vibration potential （CVP） model of biological cell under the action of ultrasound is investigated, and the mathematical expression and the interaction of the electrokinetic polarization potential of ion and cell are constructed. Based on the electrokinetic model of the cell suspension, an electrokinetic measurement system using the step ultrasonic signal is set up. Via the vibration potential measurement of the solution of NaCl, it shows that the ion vibration potential （IVP） gets direct proportional to the ion concentration. But the IVP wavily drops with the increasing ion concentration once the ion concentration increases to a certain level, or even increases with reversed-phase due to the action of the electrokinetic polarization of particle of ultrasonic condensation. The vibration potential measurement of the chicken blood cell suspension shows that the total vibration potential （TVI） of the cell suspension decreases with the increasing cell concentration in the cell suspension in low concentration. When the cell concentration gets up to 6 ×105 mL-1 , the TVI begins to increase with the increasing cell concentration, henceforth, the electrokinetic polarization of cell primarily facilitates TVI increase.