Measurement of ultrasmall volumes using anodic stripping voltammetry

This paper discusses a new and effective method for small volume determination. The benefits of working with small volumes are numerous and include using less material, generating less waste, increased functionality in less space, portability, and high throughput. As sample size decreases, measuring its volume becomes more challenging. The most prevalent method for small volume determination is visual inspection. The method presented in this paper is precise, more quantitative, and adaptive to many solution geometries, because it is based on a coulometric approach. Demonstration of this method is performed on volumes of approximately 1 nL containing silver and using a self-contained microcavity device that contains multiple electrodes. The silver is "exhaustively" deposited during a cathodic potential step, followed by anodic stripping voltammetry. It is expected that an even faster and more accurate analysis of volumes much smaller than those evaluated here is easily possible using this approach.