Electrical Immunoassays for Clinical Diagnostic Applications

Abstract

Format

This is a copy of the slides presented at the meeting but not formally written up for the volume.

Abstract

Proteomics based clinical diagnostics systems utilize the principle of protein identification as a means of biomarker profiling for disease diagnosis. The current standardized immunoassay techniques such as Enzyme linked Immunosorbent Assays (ELISA) are based on the fluorescent detection of the antibody (Ab)-antigen (Ag) binding event. These techniques are expensive; time consuming requiring a large sample volume. We present here two electrical immunoassay techniques that can potentially used for the rapid, multiplexed diagnosis of proteins for disease identification. The first technique involves the use of nanoporous templates in conjunction with microfabricated platforms with metallic base electrodes resulting In the formation of a “nanowell” assay system that is analogous to the micro titer well plate system. The detection of the formation of binding complex is achieved by capacitive measurement techniques. The dynamic range and the calibration of the device has been performed with respective to the current gold standard in proteomics. The second technique involves the use of microscale carriers to transport ab’s to sensing sites on microfabricated base platforms. The binding of the Ag’s to the Ab’s coupled to the carriers’ results in measurable voltage changes that are recorded in a real time manner. The calibration and the dynamic range of this device has also been determined. Both these techniques demonstrate potential as early diagnostic devices and their performance in detection of clinically relevant proteins is demonstrated.