Wheeler Kaden, Gott Joseph, Roehrich Brian, Chung Julia, Kajal Kajal, Syzdek Jaroslaw, Hespanha Joao, Sepunaru Lior
Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California 93106, United States.
Interdepartmental Program in Biomolecular Science and Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, United States.
ACS Electrochem. 2025 Apr 3;1(4):552-559. doi: 10.1021/acselectrochem.4c00117. Epub 2025 Feb 22.
Measurement of small currents is often impeded by a suboptimal signal-to-noise ratio, largely due to background noise. This background noise significantly constrains the range of catalysts accessible for interrogation via micro- and nanoscale electrochemistry. In response, this work reveals how background noise scales in the presence of induced Faradaic reactions. We measured noise under a series of electrochemical conditions and discovered that the induced noise from a Faradaic reaction scales directly with current. Complementary electrochemical impedance spectroscopy measurements demonstrated that diffusional resistance dictates the noise of Faradaic reactions, independent of the electrochemical mechanism. The noise source is thermal in origin and propagates in a predictable trend, which is inversely proportional to the equivalent diffusional resistance of the analyte. The universality of the observed phenomenon allows for better deconvolution of measured charge from background noise, thus assisting in achieving higher resolution and measurement precision, which is a key in micro- and nanoscale electrochemical measurements.
小电流的测量常常受到信噪比欠佳的阻碍，这主要是由于背景噪声所致。这种背景噪声显著限制了可通过微纳尺度电化学进行检测的催化剂范围。作为回应，这项工作揭示了在存在诱导法拉第反应的情况下背景噪声是如何变化的。我们在一系列电化学条件下测量了噪声，发现法拉第反应产生的诱导噪声与电流直接成正比。互补的电化学阻抗谱测量表明，扩散电阻决定了法拉第反应的噪声，与电化学机制无关。噪声源源于热，且以可预测的趋势传播，该趋势与分析物的等效扩散电阻成反比。所观察到现象的普遍性有助于更好地从背景噪声中解卷积测量电荷，从而有助于实现更高的分辨率和测量精度，这是微纳尺度电化学测量中的关键。
