Glassy carbon nanofibers(GCNFs)are considered promising candidates for the fabrication of nanosensors for biosensing applications.Importantly,in part due to their great stability,carbon electrodes with sub-10 nm nanog...Glassy carbon nanofibers(GCNFs)are considered promising candidates for the fabrication of nanosensors for biosensing applications.Importantly,in part due to their great stability,carbon electrodes with sub-10 nm nanogaps represent an attractive platform for probing the electrical characteristics of molecules.The fabrication of sub-10 nm nanogap electrodes in these GCNFs,which is achieved by electrically stimulating the fibers until they break,was previously found to require fibers shorter than 2µm;however,this process is generally hampered by the limitations inherent to photolithographic methods.In this work,to obtain nanogaps on the order of 10 nm without the need for sub-2µm GCNFs,we employed a fabrication strategy in which the fibers were gradually thinned down by continuously monitoring the changes in the electrical resistance of the fiber and adjusting the applied voltage accordingly.To further reduce the nanogap size,we studied the mechanism behind the thinning and eventual breakdown of the suspended GCNFs by controlling the environmental conditions and pressure during the experiment.Following this approach,which includes performing the experiments in a high-vacuum chamber after a series of carbon dioxide(CO 2)purging cycles,nanogaps on the order of 10nm were produced in suspended GCNFs 52µm in length,much longer than the~2µm GCNFs needed to produce such small gaps without the procedure employed in this work.Furthermore,the electrodes showed no apparent change in their shape or nanogap width after being stored at room temperature for approximately 6 months.展开更多
基金This work was supported by grants from CONACYT(Mexico)project 241458(CB-2014-01)the Sensors and Devices Group of Tecnologico de Monterrey,Mexico(002EICII01).
文摘Glassy carbon nanofibers(GCNFs)are considered promising candidates for the fabrication of nanosensors for biosensing applications.Importantly,in part due to their great stability,carbon electrodes with sub-10 nm nanogaps represent an attractive platform for probing the electrical characteristics of molecules.The fabrication of sub-10 nm nanogap electrodes in these GCNFs,which is achieved by electrically stimulating the fibers until they break,was previously found to require fibers shorter than 2µm;however,this process is generally hampered by the limitations inherent to photolithographic methods.In this work,to obtain nanogaps on the order of 10 nm without the need for sub-2µm GCNFs,we employed a fabrication strategy in which the fibers were gradually thinned down by continuously monitoring the changes in the electrical resistance of the fiber and adjusting the applied voltage accordingly.To further reduce the nanogap size,we studied the mechanism behind the thinning and eventual breakdown of the suspended GCNFs by controlling the environmental conditions and pressure during the experiment.Following this approach,which includes performing the experiments in a high-vacuum chamber after a series of carbon dioxide(CO 2)purging cycles,nanogaps on the order of 10nm were produced in suspended GCNFs 52µm in length,much longer than the~2µm GCNFs needed to produce such small gaps without the procedure employed in this work.Furthermore,the electrodes showed no apparent change in their shape or nanogap width after being stored at room temperature for approximately 6 months.
