Composite Material Modified Electrode Used The Measurement Of Rice Cells Viscoelasticity

In this paper,rice suspension cells were used as the research object,3-hydroxypenylboric acid（3-PBA）and poly-L-lysine（PLL）were copolymerized on the surface of gold electrode quartz crystal by electrochemical cyclic voltammetry to adhere to rice suspension cells,and the viscoelastic changes of rice suspension cells under stresses of different concentrations of Cu²⁺and saline-alkali were monitored in real time by QCM technique.The main results are summarized as follows:（1）Copolymer films of 3-hydroxyphenylboric acid（3-PBA,0.5mmol/L,p H=7.4 PBS）and poly-L-lysine（PLL,0.1%,w/v）with positive charge were prepared on the surface of gold electrode quartz crystal by electrochemical cyclic voltammetry and acted on rice suspension cells.The results of cyclic voltammetry,electrochemical impedance spectroscopy and optical microscope observation showed that rice suspension cells could adhere to the PLL-poly（3-PBA）/Au sensing interface effectively,which was further verified by the results of quartz crystal microbalance.（2）After adhering about 50,000 rice suspension cells to the 8MHz quartz crystal gold electrode modified by copolymerization,the viscoelastic properties of rice suspension cells under stresses of different concentrations of Cu²⁺were monitored in real time.The results showed that at lower concentrations of Cu²⁺（10～50μmol/L）,the metal ions are poisonous,the cells start a defense mechanism with increased lignin on the cells’walls which makes the cells harder.When the concentration of Cu²⁺is higher（100μmol/L）,the toxicity of metal ions exceeds the detoxification ability of the cells,thereby destroying the cell wall structure and making the cells softer.（3）The QCM technology was used to monitor the changes of viscoelasticity of rice suspension cells under different concentrations of salt-alkali stresses in real time.Alkaline stress increases the high p H stress in additional to salt stress,so that there was an opposite trends of frequency resistance responses observed under the effects of salt and alkali stresses.However,under the effect of either salt or alkali stress,the cells first became softer and then harder.The osmotic stress generated under saline-alkali stress（10～50 mmol/L）depolymerizes both cytoskeletal microfilaments and microtubules,and then the cytoskeletal components re-polymerize.