Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)


Electrical Engineering

First Advisor

Dr. Hasina Huq

Second Advisor

Dr. Heinrich Foltz

Third Advisor

Dr. Karen Lozano


An amperometric biosensor using AlGaN/GaN based HEMT devices is constructed experimentally and validated through analytical and numerical techniques for detection of a key protein in allograft rejection (Human MIG/CXCL9). The prototype developed provides a reliable sensing platform that will allow label-free and marker-free detection. By exploiting characteristics unique to AlGaN/GaN based HEMT devices, a floating gate configuration is employed to allow reliable sensing without the need for any reference electrode. Self-assembled monolayers (SAM) are formed at the gate surface by using a crosslinker (DSP) to allow for appropriate immobilization of target antibodies. A theoretical analytical and numerical model is developed to explain the mechanism of action of the proposed biosensor. Furthermore, other issues such as repeatability, influence of the substrate, threshold shifting, and device packaging are addressed. Finally, an experimental circuit is constructed with the previously prepared biosensor to validate the claims made in this thesis.


Copyright 2014 Hector Trevino II. All Rights Reserved.

Granting Institution

University of Texas-Pan American