Measuring conductance of phenylenediamine as a molecular sensor

We report experimental measurements of molecular conductance as a single molecular sensor by using scanning tunneling microscope-based break-junction (stm-bj) technique. the gap was created after au atomic point contact was ruptured,and the target molecule was inserted and bonded to the top and bottom electrodes. we successfully measured the conductance for a series of amine-terminated oligophenyl molecules by forming the molecular junctions with au electrodes. the measured conductance decays exponentially with molecular backbone length,enabling us to detect the type of molecules as a molecular sensor. furthermore,we demonstrated reversible binary switching in a molecular junction by mechanical control of the gap between the electrodes. since our method allows us to measure the conductance of a single molecule in ambient conditions,it should open up various practical molecular sensing applications. © 2015 taekyeong kim and tae hyun kim.