Fabrication of conducting open nanoshells

Abstract

A method involving ion milling is demonstrated to fabricate open-nanoshell suspensions and open-nanoshell monolayer structures. Ion milling technology allows the open-nanoshell geometry and upward orientation on substrates to be controlled. Substrates can be fabricated covered with stable and dense open-nanoshell monolayer structures, showing nanoaperture and nanotip geometry with upward orientation, that can be used as substrates for SERS-based biomolecule detection.

1 - 23 . (canceled) 
     
     
         24 . A substrate having a layer thereon, the layer comprising nanoparticles, each of the nanoparticles comprising a conductive open shell, wherein substantially all of the nanoparticles have an open part of their conductive open shell facing away from the substrate. 
     
     
         25 . The substrate having a layer thereon according to  claim 24 , wherein the nanoparticles further comprise a dielectric core partially surrounded by the conductive open shell. 
     
     
         26 . The substrate having a layer thereon according to  claim 25 , wherein the dielectric core comprises SiO 2 . 
     
     
         27 . The substrate having a layer thereon according to  claim 24 , wherein the substrate is flat and wherein substantially all of the nanoparticles have edges of the open part of their conductive open shell substantially in a plane making an angle of from 0° to 45° with a plane of the substrate. 
     
     
         28 . The substrate having a layer thereon according to  claim 24 , wherein the open part of the conductive open shells corresponds to removal of from 5% to 45% of a surface area of the shell. 
     
     
         29 . The substrate having a layer thereon according to  claim 24 , wherein the conductive open shells comprise at least one material selected from the group consisting of Au, Ag and Al. 
     
     
         30 . The substrate having a layer thereon according to  claim 24 , wherein the nanoparticles are immobilized on the substrate via a functionalization layer present on the substrate. 
     
     
         31 . The substrate having a layer thereon according to  claim 24 , wherein the nanoparticles are not embedded in the substrate. 
     
     
         32 . The substrate having a layer thereon according to  claim 24 , wherein the substrate having a layer thereon comprises a component of an imaging device. 
     
     
         33 . The substrate having a layer thereon according to  claim 24 , wherein the substrate having a layer thereon comprises a component of an optical spectroscopy device. 
     
     
         34 . The substrate having a layer thereon according to  claim 24 , wherein the optical spectroscopy device is configured to employ surface-enhanced Raman spectroscopy-based biomolecule detection. 
     
     
         35 . A method for fabricating a substrate having a layer thereon, the method comprising:
 depositing a layer of nanoparticles on a substrate surface, wherein the nanoparticles each comprise a dielectric core and a complete conductive shell around the dielectric core; and   removing a part of each conductive shell at an area of the nanoparticle facing away from the substrate surface.   
     
     
         36 . The method according to  claim 35 , further comprising coating the substrate surface having nanoparticles thereon with a fluid coating configured to form a solid matrix embedding the nanoparticles, wherein coating is conducted between depositing and removing, and wherein removing comprises, after the solid matrix is formed, removing a part of the solid matrix at a surface thereof facing away from the substrate, thereby removing a part of each conductive shell. 
     
     
         37 . The method according to  claim 35 , wherein the nanoparticles are deposited in a fluid coating configured to form a solid matrix embedding the nanoparticles, and wherein removing comprises, after said solid matrix is formed, removing a part of the solid matrix at a surface thereof facing away from the substrate, thereby removing a part of each conductive shell. 
     
     
         38 . The method according to  claim 35 , wherein removing is performed via a directional removing technique, preferably a directional etching technique. 
     
     
         39 . The method according to  claim 38 , wherein the directional removing technique is a directional etching technique. 
     
     
         40 . The method according to  claim 38 , wherein the directional removing technique is ion milling. 
     
     
         41 . The method according to  claim 35 , further comprising chemically functionalizing the substrate, wherein chemically functionalizing is conducted prior to depositing. 
     
     
         42 . The method according to  claim 35 , further comprising removing the dielectric cores from the nanoparticles, each nanoparticle comprising a conductive open shell. 
     
     
         43 . A method for producing nanoparticles comprising a conductive open shell, comprising:
 depositing a layer of nanoparticles on a substrate surface, wherein the nanoparticles each comprise a dielectric core and a complete conductive shell around the dielectric core; and   removing a part of each complete conductive shell at an area of the nanoparticle away from the substrate surface, thereby forming nanoparticles comprising a conductive open shell.   
     
     
         44 . The method according to  claim 43 , wherein removing is performed via a directional removing technique, the method further comprising removing the conductive open shells from the substrate. 
     
     
         45 . The method according to  claim 44 , wherein the directional removing technique is a directional etching technique. 
     
     
         46 . The method according to  claim 44 , further comprising treating a medical condition in a patient by thermotherapy using the removed conductive open shells. 
     
     
         47 . The method according to  claim 44 , further comprising conducting biomedical imaging of a patient using the removed conductive open shells. 
     
     
         48 . The method according to  claim 44 , further comprising fabricating a surface plasmon resonance biosensor incorporating the removed conductive open shells.