Sensitive and quantitative technologies for molecular characterization of scant cells in easily accessible bodily sources such as fine needle aspirates, biopsies, whole blood, saliva and urine can potentially have significant impacts in life sciences and clinical practice. Current laboratory procedures used for cancer biomarker testing require collection of the body fluids and aspirates, transfer of those materials to the laboratory for testing with turn-around-times in the range of a day to several days. This sometimes could lead to phenotypic/apoptotic changes of sampled cells. This project will develop a nanotube-antibody biosensor arrays for rapid detection of circulating cancer cells in blood that can identify surface markers directly on cancer cells within 15 minutes. The project will seek to accomplish the following specific aims: 1. Detection of molecular surface receptors namely IGF1R, Her2, and EpCAM in BT474, MCF7, SKBR3 and MCF10A cancer cells in blood. Creation of expression level and malignancy maps to rapidly profile the circulating tumor cells in blood within minutes. 2. Use nanoneedle probes to investigate the binding forces of receptors to antibodies for non-specific and specific interactions to create an expression level and malignancy maps based on interaction forces. 3. Demonstrate that our biosensors have the detection sensitivities and specificities that is comparable to standard immunoassays such as ELISA. Blood from breast cancer patients will be tested using both standard technique and our nanotube-biosensor technique and statistical correlation of these data will help standardize this technique for future testing. The successful accomplishment of these aims will lead to developing a quick and very inexpensive test that uses a very small quantity of blood (micro-liter or less) to detect tumor cells on a patient's blood circulation in a matter of a few minutes. This inexpensive test definitely has a strong commercial potential as we have plans for commercialization of the products after proofing the concept during the period of this proposal. PUBLIC HEALTH RELEVANCE: This project will develop nanotube-antibody biosensor arrays for rapid profiling of circulating cancer cells in blood within minutes. Based on the sensor arrays, a device will be developed that will be used in detecting and profiling circulating breast cancer cells in blood. This new technology will be compared against standard immunoassays such as ELISA.