Melamine assay methods and systems

A method of detecting melamine comprising:

• providing a quantity of SERS-active particles;
• providing a quantity of magnetic particles;
• associating one or more SERS-active particles with one or more magnetic particles;
• mixing a solution containing melamine with the SERS-active particles and magnetic particles;
• magnetically concentrating the magnetic particles;
• and
• detecting a surface enhanced Raman spectrum of the melamine.

A method of detecting a molecule of interest comprising:

• providing a quantity of SERS-active particles;
• providing a quantity of a SERS-active standard having a known SERS spectrum;
• mixing a solution containing the molecule of interest with the SERS-active particles and the SERS-active standard;
• detecting a surface enhanced Raman spectrum of the molecule of interest;
• and
• detecting a surface enhanced Raman spectrum of the SERS-active standard.

An assay system comprising:

• a quantity of SERS-active particles;
• a quantity of a SERS-active standard;
• a container for mixing a solution of a molecule of interest with the SERS-active particles and the SERS-active standard;
• and
• a SERS reader configured to obtain a SERS spectrum of the molecule of interest and a SERS spectrum of the SERS-active standard.