The GaAs/AIGaAs-Based Extended Gate HEMT Cardiac Troponin-I Biosensor: Design, Mechanism and Clinical Detection

Herein, we designed several structures of GaAs/AIGaAs extended gate high electron mobility transistors (EG-HEMT) for cTnI detection, in order to explore the mechanism of bio-detection, the limit of detection (LOD) as well as the application in clinical detection. The experiment carried out that 50y structure of EG-HEMT biosensor, whose extended electrode is 50 times as large as the gate, has highest biological regulation ability (delta). Meanwhile, the concentration range of cTnI detection using 50y EG-HEMT biosensor is about 100 fg ml(-1) to 10 mu g ml(-1), which is much broader than that of Unicel Dx1800 (usually be used in clinical detection). Furthermore, due to the influence of parasitic resistance and other factors, delta increases with the increase of y, but the rising rate of delta decreases at the same time. By comparing the detecting results of clinical samples, 30y EG-HEMT is the best in the detection of cTnI concentration with a relative error of 6%. In a higher concentration range, it is more accurate than that of the Unicel Dx1800, breaking through its limit.

Automated summary

Different structures of EG-HEMT were designed for cTnI detection, with 50y structure showing the highest biological regulation ability and a broader detection range. The biological regulation ability increases with increasing y value, but the growth rate decreases. 30y EG-HEMT performs best in clinical sample detection of cTnI concentration.