Measurement sample preparation method, analysis method, reagent, and reagent kit

An analysis method for analyzing analytes in a sample using a spectroscopic analysis, the method comprising:

• preparing a measurement sample comprising, wherein the preparing comprises:
• contacting the analytes with linkers to bind the analytes to the linkers, whereby a plurality of complexes are formed, each complex having the analyte and the linker bound to the analyte;
• contacting the complexes with metal nanoparticles to bind the complexes to the metal nanoparticles, whereby a plurality of first aggregates are formed in a solution, each first aggregate having the metal nanoparticle and the complex bound to the metal nanoparticle;
• and
• adding an inorganic salt or an acid to the solution containing the plurality of the first aggregates, whereby a second aggregate is formed, the second aggregate consists of a plurality of the analytes, a plurality of the linkers and a plurality of the metal nanoparticles;
• obtaining an optical spectrum from the second aggregates as a measurement sample;
• and
• outputting information about a type of the analyte in the second aggregate on the basis of the obtained optical spectrum,
• wherein the analyte is at least one substance selected from the group consisting of a single amino acid, a nucleic acid, a catecholamine, a polyamine, an organic acid, an extracellular vesicle and a virus.