Electrical XPS Meets Bio: In-Situ Chemo-Electrical Sensing and Activation of Organic Materials

Abstract

X-ray photoelectron spectroscopy (XPS) is a popular analytical technique in material sciences thanks to its versatile coverage of broad energy ranges and the reliability of its quantitative compositional analysis. Hence, tailoring the XPS capabilities into research frontiers of biological systems and nature-inspired materials can potentially become of great value. However, XPS applications to bio/organic systems encounter critical inherent challenges, specifically amplified by the rich nuances that are at the heart of biological functions. The present mini review describes some of these difficulties, showing that by combining electrical-sensing capabilities in-situ to the standard XPS chemical analysis, diverse and effective solutions are proposed. A related method, termed chemically resolved electrical measurements (CREM), is described and case study examples are provided, ranging from self-assembled monolayers of small molecules to relatively large supramolecular sugars and proteins. Detailed discussion is dedicated to specimen stability issues, charge capturing and hot-charge transport functionalities, for which the CREM approach proposes particularly attractive capabilities and a template for advanced characterization strategies.