Biomarker detection system

A localised surface plasmon resonance (LSPR) nanopillar assembly for use in sensing the presence of a biomarker when attached to a quantum dot, comprising:

• a) a substrate;
• b) an array comprising:
• i) a plurality of metallic LSPR nanopillars, each of the nanopillars consists of a metallic nanopillar body;
• and
• ii) at least one polymer spacer attached to the nanopillars;
• and
• c) an antibody attached to the at least one polymer spacer;
• wherein a combined height of the polymer spacer and antibody is such that, when in use with the biomarker and the quantum dot, the quantum dot is in an LSPR region of the nanopillar;
• and
• each of the at least one polymer spacer comprises a discrete linear or non-linear polymer molecule having at least two opposed terminal ends, a first terminal end being attached to the nanopillar and a second spaced and opposed terminal end being attached to the antibody;
• wherein the polymer spacer is a polyethylene glycol (PEG) spacer;
• wherein the PEG spacer is PEG2-100;
• wherein the metallic nanopillar body has a length of about 50 nm to about 250 nm, width of about 50 nm to about 250 nm, and height of about 20 nm to about 100 nm;
• wherein the nanopillar array comprises a plurality of metallic nanopillars, in which a pitch of the nanopillar array is about 150 nm to about 500 nm.