Proteomic chips for rapid, low-cost molecular identification and quantitation of target proteins in blood will be developed by fabricating silicon microchips containing aptamer arrays. The blood sample will be drawn painlessly via strong, flexible, and fracture resistant silicon microneedles integrated into the microchips. The sample volume will be only 200 nanoliters, and multiple measurements will be made simultaneously on this sample by fluorescent readout of proteins selectively bound to the array. The silicon microchips and the electronic instrument to perform the sampling step and optical readout will be adapted from devices currently being made by the proposer for diabetic blood glucose self-testing. Aptamers, which are globular ssDNA oligonucleotides capable of performing immunoassays analogously to antibodies, will be produced by the SELEX (systematic evolution of ligands by exponential enrichment) process and supplied by a sub-contractor, Somalogic with the advice and assistance of Dr. Larry Gld, under whose direction SELEX was developed. In contrast to antibodies, aptamers are produced in vitro, by design. Use of aptamer arrays for molecular recognition, proven silicon chip technology, and a universal fluorescent readout technique permit rapid development of proteomic chips capable of assaying multiple proteins in blood with high sensitivity and specificity. Minimally invasive aptamer array chips capable of making physiologically meaningful assays will result by the end of the second year of this R&D program.
These proteomic chips will be widely used for painless blood sampling and automatic performance of immunoassays for screening for infectious diseases, early detection of exposure to biological warfare agents low cost painless monitoring for cancer markers, monitoring of cardiac markers, maintenance of correct levels of therapeutic drugs, and proteomics research.