Nmr systems and methods for the rapid detection of analytes

A method of monitoring one or more of analytes in a liquid sample derived from a patient for the diagnosis, management, or treatment of a medical condition in a patient, the method comprising:

• (a) combining with the liquid sample from 1×106 to 1×1013 magnetic particles per milliliter of the liquid sample, wherein the magnetic particles have a mean diameter of from 150 nm to 1200 nm and a T2 relaxivity per particle of from 1×108 to 1×1012 mM−1s−1, and wherein the magnetic particles have binding moieties on their surfaces, the binding moieties operative to alter the specific aggregation of the magnetic particles in the presence of the one or more analytes or a multivalent binding agent;
• (b) placing the liquid samples in a device, the device comprising a support defining a well for holding the liquid sample comprising the magnetic particles and the one or more analytes, and having an RF coil disposed about the well, the RF coil configured to detect a signal produced by exposing the liquid sample to a bias magnetic field created using one or more magnets and the RF pulse sequence;
• (c) exposing the sample to the bias magnetic field and the RF pulse sequence;
• (d) following step (c), measuring the signal;
• (e) on the basis of the result of step (d), monitoring the one or more analytes;
• and
• (f) using the result of step (e) to diagnose, manage, or treat the medical condition.