Nanoparticle array with tunable nanoparticle size and separation

A method of producing a nanoparticle array comprising:

• (a) applying a block copolymer onto a substrate to give a thin film;
• (b) reacting the applied block copolymer with a functionalizing agent;
• and
• (c) immersing the thin film of (b) in a nanoparticle suspension to give a nanoparticle array;
• wherein the nanoparticles are dispersed on the block copolymer.

A method for enhancing a Raman signal of an analyte comprising:

• (a) providing a nanoparticle array comprising:
• (1) a block copolymer applied to a substrate, wherein the block copolymer comprises at least two polymer blocks, and wherein at least one of polymer blocks has been functionalized;
• and
• (2) a plurality of nanoparticles on the block copolymer, wherein the nanoparticles are dispersed on the block copolymer, and wherein the nanoparticles adhere to at least 90% of the block copolymer domains that have been functionalized;
• (b) adhering an analyte to the nanoparticle array;
• (c) exposing the analyte to incident light of an excitation wavelength that overlaps with the metallic nanoparticle plasmon resonance band;
• and
• (d) detecting the optical signal of the analyte as Raman scattered radiation;
• wherein the optical signal of the analyte is enhanced compared to the signal when the analyte is exposed to incident light in the absence of the nanoparticle array.

A method of detecting an analyte comprising:

• (a) providing a nanoparticle array comprising:
• (1) a block copolymer applied to a substrate, wherein the block copolymer comprises at least two polymer blocks, and wherein at least one of polymer blocks has been functionalized;
• and
• (2) a plurality of nanoparticles on the block copolymer, wherein the nanoparticles are dispersed on the block copolymer, and wherein the nanoparticles adhere to at least 90% of the block copolymer domains that have been functionalized;
• (b) adhering an analyte to the nanoparticle array;
• (c) exposing the analyte to incident light of an excitation wavelength that overlaps with the metallic nanoparticle plasmon resonance band;
• and
• (d) detecting the presence of the analyte by monitoring the presence or absence of a known Raman spectrum for the analyte.