NMT历史上的今天丨中农学者：非损伤NMT设备检测K+流的稳定性

​​NMT作为生命科学底层核心技术，是建立活体创新科研平台的必备技术。2005年~2020年，NMT已扎根中国15年。2020年，中国NMT销往瑞士苏黎世大学，正式打开欧洲市场

期刊：Information Processing in Agriculture
主题：非损伤NMT设备检测K+流的稳定性

标题：The calibration model in potassium ion flux non-invasive measurement of plants in vivo in situ

检测指标：K+流速

作者：中国农业大学王忠义

英文摘要

NMT (Non-invasive Micro-test Technology) provides a  novel electrophysiological tool which can non-invasively measure the  dynamic influxes and effluxes of ions caused by the diffusion along the  concentration gradients in vivo.

However, in this technique ion  fluxes are converted to voltage signals using an ion selective  microelectrode at a small amplitude of μV, which is easy to be  interfered by the ambient noise. Hence, effective solutions to the  suppression of noise and calibration of ion flux measurement system are  very important for this method. A K+-selective microelectrode was  constructed using liquid ion exchangers (LIX) to investigate ion  transport over plant tissue.

A standard concentration gradient  which simulates plant living cells was produced by an electrode with a  certain tip diameter, filled with a solution containing a known  K+ concentration in 100 mmol/L. An ion diffusion simulation model was  established. This model evaluated the performance of ion flux  measurement system in accuracy and reliability by comparing the  consistency of the measured value and the predicted curve. K+ fluxes  were measured within 25 minutes at each measuring point of distance 10,  20, 30, 40, 50, 80, and 100 μm from the K+ source, respectively.

It can be seen that the K+ fluxes changes little,  which indicates that ion fluxes measurement system has a reliable  stability. The study provides a theoretical basis for a new non-invasive  ion flux measurement method creation and a new sensors design.

中文摘要（谷歌机翻）

NMT（非损伤微测技术）提供了一种新型的电生理工具，可以无创地测量由于体内浓度梯度的扩散所引起的离子的动态流入和流出。

然而，在该技术中，使用离子选择微电极以小幅度的μV将离子通量转换为电压信号，这容易受到环境噪声的干扰。因此，有效的解决方案包括抑制噪声和校准离子通量测量系统。使用液体离子交换剂（LIX）构建K+选择性微电极，以研究离子在植物组织上的传输。

由具有一定尖端直径的电极产生的模拟植物活细胞的标准浓度梯度，该电极填充有含有100  mmol /  L已知K+浓度的溶液。建立了离子扩散模拟模型。该模型通过比较测量值和预测曲线的一致性来评估离子通量测量系统在准确性和可靠性方面的性能。在25分钟内分别在距K  +源10、20、30、40、50、80和100μm的每个测量点测量K+通量。

可以看出，K+通量变化很小，表明离子通量测量系统具有可靠的稳定性。该研究为新的非侵入式离子通量测量方法的创建和新的传感器设计提供了理论基础。

Fig. 8. K+ flux measured at each known position (vibration amplitude Δx is 10