Control of molecular conductance by pH

pH plays a fundamental role in regulating various processes occurring in ecosystems, biological organisms, and chemistry laboratories, and lately, has been observed to drastically impact material electronic properties at the single molecule level. The use of pH represents one route both to investigate the fundamental charge transport processes at nanoscale junctions and to create new electronic device functions. In this review, we describe how pH affects and controls the conductance of various single molecule junctions, their underlying mechanisms and technological implications, and how such rules of pH-property relationship need to be further developed so we can ultimately use pH as a routine method to control single molecule conductance.