DNA Computing

A microscopy system was acquired for molecular detection using molecular motor-driven nanodevices. This state of the art system incorporates a motorized stage that can move to successive adjacent fields of view, and stitch the digital color photos for analysis. The detection system utilizes the molecular motor attached to a slide and a gold nanorod that is visible by darkfield microscopy. Assembly of each nanodevice is dependent upon the presence of one molecule of target that bridges between motor and nanorod. Zeptomole sensitivity of target DNA is achieved without PCR or other means of amplification via molecular motor-dependent rotation. We have now demonstrated simultaneous, multiplexed detection of sequence specific DNA, RNA, and proteins unique to MRSA on the same platform with three separate colors of gold nanorods each having a different functionalization. We have also demonstrated the ability to differentiate between Staphylococcus aureus and MRSA as well as detection of target from crude cell lysate. We have written algorithms that can analyze the stitched digital photos of fields of view, correctly identify red, green, and yellow nanorods used to detect DNA, RNA, and proteins, respectively, then rapidly quantify the amount of each target present. Assembly of a commercial prototype of the detection device is underway.