{'fraction_non_alphanumeric': 0.03434459072696051, 'fraction_numerical': 0.0, 'mean_word_length': 5.474074074074074, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Redox-probe-free scanning electrochemical microscopy combined with fast Fourier transform electrochemical impedance spectroscopy.

Scanning electrochemical microscopy (SECM) hybridized with fast Fourier transform-based electrochemical impedance spectroscopy (FFT-EIS) seems to be a powerful variation of scanning electrochemical impedance microscopy (SEIM), wherein both state-of-the-art techniques are combined (FFT-SEIM) and can be used for the investigation and treatment of tissues at single cell level. However, in most EIS-based experiments, harmful redox mediators are applied, which affect the functioning of living cells and tissues. Therefore, the development of a redox-probe-free FFT-SEIM is still a very important challenge in electrochemistry. For this reason, in this research, we have demonstrated a redox-probe-free evaluation of conducting and non-conducting surfaces by combining scanning electrochemical microscopy with FFT-EIS. It was demonstrated that using the fast Fourier transform-based FFT-EIS technique, EIS spectra could be registered much faster compared to experiments performed using the conventional EIS equipment. An ultramicroelectrode (UME) was used as a scanning electrode to ensure high spatial resolution. We have performed FFT-SEIM measurements in a redox-probe-free mode (without any additional redox probes) and have investigated several surfaces with different conductivities. The FFT-EIS equipment and the built-in software help to avoid the influence of possible formation of hydrogen bubbles on the UME. This research opens up a new avenue for the application of FFT-SEIM in the investigation of samples that are unstable and very sensitive towards redox mediators (e.g., tissues and/or living cells).