Kinetic modulation for magnetic analyte detection

A method for detecting the presence, absence, or amount of an analyte in a biological sample, the method comprising:

• (a) contacting the biological sample with a magnetic conjugate comprising a magnetic particle and a capture moiety comprising a first antibody configured to bind the analyte in the biological sample;
• (b) contacting the magnetic conjugate and the bound analyte with a reporter binding moiety comprising a second antibody and a biotin tag bound thereto, wherein the capture moiety and the reporter binding moiety bind different portions of the analyte, and wherein the reporter binding moiety is present at a concentration of about 1 nM to about 600 nM;
• (c) contacting a complex comprising the magnetic conjugate, the analyte, and the reporter binding moiety with a reporter comprising a streptavidin tag binding partner that is configured to bind the biotin tag of the reporter binding moiety, wherein the reporter comprises a particle studded with a plurality of quantum-dots, and wherein the reporter is present at a concentration of about 10 pM to about 140 pM;
• (d) applying a magnetic field to separate a detectable complex comprising the magnetic conjugate, the analyte, the reporter binding moiety and the reporter bound thereto;
• and
• (e) detecting the presence, absence, or amount of the analyte based on detection of a signal generated by the reporter.