Competitive small molecule detection assays using arrayed imaging reflectometry

A method of detection using an arrayed imaging reflectometry (AIR) sensor chip, the method comprising:

• providing an arrayed imaging reflectometry sensor chip;
• printing a probe on a surface of the sensor chip, wherein the probe comprises at least one target molecule;
• contacting the sensor chip with a sample solution comprising an antibody and the target molecule so that a portion of the antibody in the sample solution binds to the probe;
• measuring an array signal for the antibody engaged to the probe using arrayed imaging reflectometry;
• comparing the array signal for the antibody engaged to the probe to a standard response plot of a known series of target concentration AIR signals;
• and
• determining the amount of the target molecule in the sample solution when the array signal is fit to the plot of the known series of target concentration AIR signals.