Anal Chem. 2013 Aug 20;85(16):7654-8. doi: 10.1021/ac402037k. Epub 2013 Aug 6.
Direct electrochemical measurements of biological events are often challenging because of the low signal relative to the magnitude of the background and noise. When choosing a data processing approach, the frequency and phase content of the data must be considered. Here, we employ a zero-phase (infinite impulse response (IIR)) filter to remove the noise from the analytical signal, while preserving the phase content. In fast-scan cyclic voltammetry, the frequency content of the signal is a function of the scan rate of the applied waveform. Fourier analysis was used to develop a relationship between scan rate and the filter cutoff frequency to maximize the reduction in noise, while not altering the true nature of the analytical signal. The zero-phase filter has the same effect as traditional filters with regards to increasing the signal-to-noise ratio. Because the zero-phase filter does not introduce a change to ΔEpeak, the heterogeneous electron rate transfer constant (0.10 cm/s) for ferrocene is calculated accurately. The zero-phase filter also improves electrochemical analysis of signaling molecules that have their oxidation potential close to the switching potential. Lastly, a quantitative approach to filtering amperometric traces of exocytosis based on the rise time was developed.
直接电化学测量生物事件通常具有挑战性，因为信号相对于背景和噪声的幅度较低。在选择数据处理方法时，必须考虑数据的频率和相位内容。在这里，我们采用零相位（无限脉冲响应（IIR））滤波器来消除分析信号中的噪声，同时保留相位内容。在快速扫描循环伏安法中，信号的频率内容是施加波形扫描速率的函数。傅立叶分析用于开发扫描速率和滤波器截止频率之间的关系，以最大程度地降低噪声，同时不改变分析信号的真实性质。零相位滤波器在提高信噪比方面与传统滤波器具有相同的效果。由于零相位滤波器不会引入 ΔEpeak 的变化，因此可以准确计算二茂铁的非均相电子转移常数（0.10 cm/s）。零相位滤波器还改善了其氧化电位接近切换电位的信号分子的电化学分析。最后，开发了一种基于上升时间的基于定量方法的胞吐作用安培迹线滤波。
