Abstract

Antibody Microarrays for Point of Care Detection from a Single Drop of Blood

Ashutosh Chilkoti, Director, Duke University

I will discuss a point-of-care diagnostic that we have developed, in which all reagents are printed and stored on a “non-fouling”—protein and cell resistant—polymer brush. The D4 assay, involves four sequential events: (1) Dispense (droplet of blood); (2) Dissolve (printed reagents on chip); (3) Diffuse (across surface); and (4) Detect (binding event). The D4 POCT antibody (Ab) consists of microarrays printed on the polymer polymer brush yields quantitative results, with picomolar sensitivity within 30 minutes. All reagents are inkjet-printed and stored on D4 POCT cassettes, which do not require refrigeration. Upon direct application of fingerstick blood onto a cassette, analyte capture and detection occur automatically, generating a quantifiable fluorescence signal obtained by placing the cassette in a small device that magnetically attaches to a smart phone, which images and analyzes microarrays via on-board App. Examples of quantitative dose-response from whole blood will be presented. The D4 assay can be used for the diagnosis of all markers for which antibody pairs are available with a speed and sensitivity that is as good or better than commercially available point-of-care tests and is far simpler, cheaper more rugged, and does not require a cold-chain.