Analyte detection using raman spectroscopy

A method for detecting the presence of an analyte in a sample from a subject or source, said method comprising:

• providing a diagnostic substrate presenting a capture agent;
• exposing the sample to a Raman detection agent, allowing analyte in the sample, if present, to bind the Raman detection agent via an affinity component presented thereon which is specific for the analyte, thereby forming an analyte-Raman detection agent complex;
• exposing the analyte-Raman detection agent complex to the diagnostic substrate, allowing the analyte-Raman detection agent complex to bind the diagnostic substrate via the capture agent presented thereon which is specific for the analyte or the analyte-Raman detection agent complex;
• and
• detecting whether the Raman detection agent bound to the diagnostic substrate using Raman spectroscopy, whereby detection of Raman detection agent bound to the diagnostic substrate indicates the presence of the analyte in the sample;
• wherein the Raman detection agent comprises a Raman signal-enhancing metal nanoparticle carrying both a Raman reporter for producing a signal detectable by Raman spectroscopy, and the affinity component for binding the analyte.

A method for detecting the presence of an analyte in a sample from a subject or source, said method comprising:

• providing a diagnostic substrate presenting a capture agent;
• providing a Raman detection agent presenting an affinity component;
• exposing the sample simultaneously to the diagnostic substrate and the Raman detection agent, allowing the capture agent, the affinity component, and analyte in the sample, if present, to form a complex which is dependent on presence of the analyte for formation;
• and
• detecting whether the Raman detection agent bound to the diagnostic substrate using Raman spectroscopy, whereby detection of Raman detection agent bound to the diagnostic substrate indicates the presence of the analyte in the sample;
• wherein the capture agent of the diagnostic substrate is specific for the analyte or a complex formed between the analyte and the Raman detection agent;
• and
• wherein the Raman detection agent comprises a Raman signal-enhancing metal nanoparticle carrying both a Raman reporter for producing a signal detectable by Raman spectroscopy, and the affinity component for binding the analyte or a complex formed between the analyte and the capture agent on the diagnostic substrate.