Nmr systems and methods for the rapid detection of analytes

Abstract

This invention features systems and methods for the detection of analytes, and their use in the treatment and diagnosis of disease.

What is claimed is: 
     
         1 . A system for the detection of creatinine, tacrolimus, and  Candida , the system comprising:
 (a) a first unit comprising (a1) a permanent magnet defining a magnetic field; (a2) a support defining a well for holding a liquid sample comprising magnetic particles and the creatinine, tacrolimus, and  Candida  and having an RF coil disposed about the well, the RF coil configured to detect signal produced by exposing the liquid sample to a bias magnetic field created using the permanent magnet and an RF pulse sequence; and (a3) an electrical element in communication with the RF coil, the electrical element configured to amplify, rectify, transmit, and/or digitize the signal; and   (b) a second unit comprising a removable cartridge sized to facilitate insertion into and removal from the system, wherein the removable cartridge is a modular cartridge comprising (i) a plurality of reagent modules for holding one or more assay reagents; and (ii) a plurality of detection module comprising a detection chamber for holding a liquid sample comprising the magnetic particles and the creatinine, tacrolimus, and  Candida,      wherein the plurality of reagent modules comprises (i) a first population of magnetic particles having a mean diameter of from 150 nm to 699 nm, a T 2  relaxivity per particle of from 1×10 to 1×10 12  mM −1 s −1 , and creatinine antibodies conjugated to their surface; (ii) a multivalent binding agent bearing a plurality of creatinine conjugates designed to form aggregates with the first population of magnetic particles in the absence of creatinine; (iii) a second population of magnetic particles having a mean diameter of from 150 nm to 699 nm, a T 2  relaxivity per particle of from 1×10 8  to 1×10 12  mM −1 s −1 , and tacrolimus antibodies conjugated to their surface; (iv) a multivalent binding agent bearing a plurality of tacrolimus conjugates designed to form aggregates with the second population of magnetic particles in the absence of tacrolimus; (v) a third population of magnetic particles have a mean diameter of from 700 nm to 1200 nm, a T 2  relaxivity per particle of from 1×10 9  to 1×10 12  mM −1 s −1 , and having a first probe and a second probe conjugated to their surface selected to form aggregates in the presence of a  Candida  nucleic acid, the first probe operative to bind to a first segment of the  Candida  nucleic acid and the second probe operative to bind to a second segment of the  Candida  nucleic acid.