Electrode Nanogap Enhanced and Dielectrophoresis-enabled Raman Spectroscopy of Single Biomolecules with Simultaneous Real-time Electronic Monitoring

This work reports a versatile platform for manipulation and sensing of biological molecules based on electrode nanogaps, which function as dielectrophoresis-enabled molecular trapping templates as well as spectroscopic and nanoelectronic detection substrates. On a chip, an array was constructed of Ti/Al nanoelectrode pairs with gap dimensions ranging from few tens of nm to <10 nm. During the molecular trapping process, ionic current measurements across the nanoelectrodes were used to detect trapping of a protein in the gap. Concurrent recording of time-dependent Raman spectra provided evidence of molecule(s) appearing in the nanogap.