Resistive switching biodevice composed of MoS ₂ -DNA heterolayer on the gold electrode

Biomolecules have been widely studied for bioelectronic application including biosensors, biomedical devices, biocomputation devices. Among them, the resistive switching biodevices have been developed to demonstrate the resistive switching function based on biomolecules. However, resistive switching biodevices developed so far have some limitations such as narrow voltage range and low stability for practical application. In this study, a heterolayer composed of carboxyl-modified molybdenum disulfide nanoparticles (MoS ₂ ) and DNA on the gold (Au) electrode was developed to achieve a wide voltage range and high stability at the nanoscale. To fabricate the resistive switching biodevices, a DNA layer was formed on the electrode through the thiol group on the DNA. The carboxyl-modified MoS ₂ was then immobilized on the DNA layer (MoS ₂ -DNA heterolayer) through the EDC/NHS reaction. For analyzing the electrical properties, the scanning tunneling spectroscopy investigation showed the resistive switching function of a wide voltage range (4.0 V to −4.0 V) and high stability (10 days) on the MoS ₂ -DNA heterolayer of Au electrodes. The conductivity dramatically increased when the voltage reached 2.4 V, whereas the conductivity abruptly decreased when the voltage reached 0.01 V. From results, we proposed that a MoS ₂ -DNA heterolayer on Au electrode could be utilized as a nanoscale resistive switching layer for the development of nanoscale bioelectronic devices with a wide voltage range and high stability. Based on those advantages, the introduction of MoS ₂ /DNA heterolayer can offer the new direction for development of novel bioelectronic devices.