The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand.
Biomicrofluidics. 2015 Jan 29;9(1):014110. doi: 10.1063/1.4905874. eCollection 2015 Jan.
Tunable resistive pulse sensing (TRPS) has emerged as a useful tool for particle-by-particle detection and analysis of microparticles and nanoparticles as they pass through a pore in a thin stretchable membrane. We have adapted a TRPS device in order to conduct simultaneous optical measurements of particles passing through the pore. High-resolution fluorescence emission spectra have been recorded for individual 1.9 μm diameter particles at a sampling period of 4.3 ms. These spectra are time-correlated with RPS pulses in a current trace sampled every 20 μs. The flow rate through the pore, controlled by altering the hydrostatic pressure, determines the rate of particle detection. At pressures below 1 kPa, more than 90% of fluorescence and RPS events were matching. At higher pressures, some peaks were missed by the fluorescence technique due to the difference in sampling rates. This technique enhances the particle-by-particle specificity of conventional RPS measurements and could be useful for a range of particle characterization and bioanalysis applications.
可调电阻脉冲传感（TRPS）已成为一种有用的工具，可用于在微小颗粒和纳米颗粒通过薄可拉伸膜上的孔时对其进行逐个颗粒的检测和分析。我们已经对 TRPS 设备进行了适配，以便对通过孔的颗粒进行同时的光学测量。在 4.3ms 的采样周期内，对直径为 1.9μm 的单个颗粒进行了高分辨率荧光发射光谱的记录。这些光谱与在每 20μs 采样一次的电流迹线中的 RPS 脉冲进行了时间相关。通过改变静水压来控制通过孔的流速，从而确定颗粒的检测速率。在压力低于 1kPa 的情况下，超过 90%的荧光和 RPS 事件是匹配的。在较高的压力下，由于采样率的差异，荧光技术会错过一些峰。该技术增强了传统 RPS 测量的逐个颗粒特异性，并且可能对一系列颗粒表征和生物分析应用有用。
