Nanoscience-Based Electrochemical Sensors and Arrays for Detection of Cancer Biomarker Proteins

Measurement of panels of biomarker proteins in serum, tissue or saliva holds great promise for future cancer diagnostics. Broad implementation of this approach in the clinic requires new, low cost devices for multiplexed protein detection. Advanced nanomaterials coupled with electrochemical detection have provided new opportunities for development of such devices. This chapter reviews recent research in using nanoparticle labels and multiplexed detection in protein immunosensors. It focuses in part on research in our own laboratories on ultrasensitive protein immunosensors combining nanostructured electrodes with detection particles with up to 500,000 labels that detect as little as 1 fg/mL protein in diluted serum. Our most mature multiple protein detection arrays are multiplexed microfluidic devices with 8-nanostructured sensors utilizing massively labeled magnetic particles or polymers. This approach provides reliable detection for multiple proteins at levels well below 1 pg/mL, and shows excellent correlation with referee methods. The importance of validating panels of biomarkers for reliable cancer diagnostics is also stressed.