Systems and methods for detecting metal ion concentrations in subjects

A method of detecting copper in a subject, the method comprising:

• a) obtaining plasma or urine from the subject;
• b) exposing the plasma or urine to a functionalized porous aromatic polymer, wherein the functionalized porous aromatic polymer selectively captures and concentrates copper from the plasma or urine;
• c) washing the plasma or urine from the functionalized porous aromatic polymer;
• d) exposing the washed functionalized porous aromatic polymer to a solution comprising a colorimetric indicator that extracts the copper from the washed functionalized porous aromatic polymer thereby changing a color of the solution as a function of an amount of the copper in the washed functionalized porous aromatic polymer;
• and
• e) spectroscopically determining, after the exposing d), the concentration of the copper in the subject from the color of the solution by measuring a characteristic absorption wavelength of a complex between copper and the colorimetric indicator.