SBIR Phase II: Nanofluidic Reference Electrode with an Invariant Liquid Junction Potential

这一小型企业创新研究（SBIR）第二阶段是使用海军研究实验室开发的纳米通道玻璃阵列开发纳米流体流动液接（NFLJ）参比电极。当消耗电解质低于2 ml/年时，NFLJ参比电极将允许流速超过0.1 cm/sec，以阻止样品溶液反向扩散到电极中。各种具有挑战性的测试样品溶液，使用NFLJ参比品进行的电位测量变化0.5 mV，响应时间小于60秒，而使用传统参比电极进行的测量变化高达20 mV，响应时间超过1小时。NFLJ参比电极极低的电解质消耗使得手持式NFLJ pH传感器具有更高的精度和更长的使用寿命。NFLJ参比电极的高阻抗在使用现代商业pH电极时对pH测量的精度、响应时间或跨度没有可测量的影响。纳米通道玻璃纳米流体流动液体结（NFLJ）为参比电极的设计和构造增加了新的维度。NFLJ设计分离流量和流速的独特能力将为科学家提供一种工具，用于研究参比电极行为作为流量，速度和电阻的函数。这将有助于发展一个更基本的了解传质对液接电位的影响。初步结果表明，速度是稳定的潜力的关键参数。

This Small Business Innovative Research (SBIR) Phase II is for the development of nanofluidic-flowing liquid junction (NFLJ) reference electrodes using nanochannel glass arrays developed by the Naval Research Laboratory. While consuming electrolyte at less than 2 ml/yr, the NFLJ reference electrodes will allow a flow at velocities of over 0.1 cm/sec to impede back diffusion of sample solution into the electrode. A variety of challenging test sample solutions, potentiometric measurements made with NFLJ references varied 0.5 mV with response times of less than 60 seconds while measurements made with conventional reference electrodes varied up to 20 mV with response times of over one hour have already been completed. The NFLJ reference electrode's exceedingly small electrolyte consumption makes possible handheld NFLJ pH sensors with significantly higher precision and longer operational life. The high impedance of NFLJ reference electrodes, when using modern commercial pH electrodes, has no measurable effect on the precision, response time, or span of the pH measurement.The nanochannel glass nanofluidic-flowing liquid junction (NFLJ) adds a new dimension to the design and construction of reference electrodes. The unique ability of the NFLJ design to separate flow volume and flow velocity will provide scientists with a tool for investigating reference electrode behavior as a function of flow, velocity, and resistance. It should help to develop a more fundamental understanding of mass transfer effect on liquid junction potentials. Initial results indicate that velocity is the critical parameter in stabilizing the potential.