Kinase detection with gallium nitride based high electron mobility transistors

Abstract

A label-free kinase detection system was fabricated by the adsorption of gold nanoparticles functionalized with kinase inhibitor onto AlGaN/GaN high electron mobility transistors (HEMTs). The HEMTs were operated near threshold voltage due to the greatest sensitivity in this operational region. The Au NP/HEMT biosensor system electrically detected 1 pM SRC kinase in ionic solutions. These results are pertinent to drug development applications associated with kinase sensing. V C 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4812987] Quantification of cellular or tissue kinome activity is important in basic cell biology research 1 and drug development. 2 Label-free methods of kinome activity profiling are ideal due to elimination of artifacts caused by changes to kinase characteristics with labeling. 3 An important label-free method of kinome activity measurement is the kinase affinity assay. In this method, cell lysates are exposed to beads functionalized with small molecule kinase inhibitors that bind kinases in the cell lysate. The kinases are removed from the beads by elution, and the kinase profile is identified by mass spectrometry. The factors that affect kinome activity profiles are the amount of kinase present in the cell lysate and the kinase affinity to the inhibitor beads. 2 Affinity is in turn affected by kinase activation state as regulated by phosphorylation. 2,3 Basic science and clinical applications exist for the kinase affinity assay. An example basic science application was the monitoring of cell cycle kinase phosphorylation status. 1 An example clinical application was a triple negative breast cancer (TNBC) drug screening study. 2 This study monitored changes in the kinome activity profile of TNBC cells with exposure to a MEK inhibitor drug. The kinome activity data guided selection of a combination of kinase inhibitor drugs in conjunction with the MEK inhibitor that resulted in decreased drug resistance compared to using any of the drugs alone. 2 Monitoring of the entire kinome gave a better overall view of drug efficacy than by monitoring the activity of a single kinase where drug resistance often develops by compensatory upregulation of uninhibited kinases. 2 Another clinical application of the kinase affinity assay was in drug development through determining kinase inhibitor drug targets. 3 Cell lysates were treated with soluble kinase inhibitors, and the lysates were exposed to the affinity beads. The soluble drug bound its target kinases, and the remaining kinases had their ATP binding sites available to bind the beads of the affinity assay. 3 The kinases with a decreased representation based on mass spectrometry following drug treatment were identified as the drug targets. 3 In this proof-of-concept report, we have demonstrated label-free detection of a kinase by a nanoparticle (NP)/high electron mobility transistor (HEMT) biosensor system. This detection method excluded the complication of a sequential kinase affinity assay followed by mass spectrometry analysis. Gold (Au) NPs w...

Highly sensitive extended gate-AlGaN/GaN high electron mobility transistor for bioassay applications

“…The main factor of the EG-AlGaN/GaN HEMT which may enhance the device performance in this situation, we suppose, is the sensing area. This is because it was reported that more surface receptors lead to a better electrical parameter of sensitivity, 24,25 and a larger sensing area has more receptors. In order to elucidate the relationship between the sensing area of the EG-AlGaN/GaN HEMT and its electrical characteristics, three different areas of the sensing pads were designed and modied (400 mm  400 mm, 500 mm  500 mm and 700 mm  700 mm).…”

An AuNPs-functionalized AlGaN/GaN high electron mobility transistor sensor for ultrasensitive detection of TNT

“…25 In a previous work, AuNPs were physically absorbed on the transistor surfaces for kinase detection. 26 The solution of AuNPs were spotted onto the wafer directly and dried in a vacuum desiccator. It was easy to cause aggregation and exfoliation from the surface.…”