Thanks to its ability to measure spatial variations in chemical properties at the nano- and micro-scales, scanning electrochemical microscopy (SECM) has been an invaluable tool in many fields of study. However, a major shortcoming of SECM that is shared by many scanning probe microscopy (SPM) techniques is the trade-off between spatial resolution and areal scan rate. For example, nanoscale imaging with conventional SECM usually requires 10’s to 100’s of hours to image areas greater than ≈ 1 mm<sup>2</sup>. This trade-off between resolution and scan time is inherent to the scanning “point probe”, or ultramicroelectrode (UME), for which its interaction with the substrate must be recorded at every (X,Y) location in a sequential, one-at-a-time manner. Improvements in areal scan rates have been achieved with 2D line probes in which many discrete UMEs are operated in parallel, although such probes have limited lateral resolution. In this talk, we present a new approach to SECM imaging that can decouple resolution from scan time by using non-local continuous line probes (CLPs) that simultaneously record signal everywhere along the length of the probe, allowing it to image large areas in a fraction of the time required by conventional UMEs. Because the CLP is a non-local probe, the signal that it records is often a convolution of signal resulting from interactions of the CLP with multiple electroactive features. In order to construct 2D SECM images from the CLP line scan data, we employ signal processing methods based on compressed sensing (CS) to disentangle these signals. CLP-SECM measurements and CS image generation have been successfully performed on samples containing various arrangements of disk electrodes with varying complexity. These results highlight the potential of using non-local SECM probes, combined with CS, to greatly improve areal scan rates without loss in resolution.<br/> <br/>

SECM with high areal scan rates using continuous line probes and compressed sensing

253rd National Meeting (2017)

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