Highly Sensitive Tungsten Oxide Thin Film-Based Field-Effect Transistor for Real-Time Monitoring of Dissolved Ammonia in Human Plasma

Field-effect transistors (FETs) based on metal-oxide thin film have the advantage of excellent sensitivity, fast response, miniaturized size, and compatibility with bio-analytes. In this work, a highly responsive FET biosensor is fabricated based on tungsten trioxide (WO3) thin film to detect the physiological concentration of total ammonia (ammonium NH4+ and NH3) in human body fluids. The elevated level of ammonia in the body fluids indicates damage or improper functioning of organs mainly the liver. Thus, real-time monitoring of ammonia concentration in human body fluid acts as a prognostic marker for liver disorders. The fabricated FET device shows reliable and accurate results for ammonia sensing with the highest response of 498 at 100 mu M and a limit of detection of 6 mu M. This device measures the ammonia in body fluid faster than available techniques and shows a high response towards ammonia in commercially available human plasma. This is also capable of real-time detection of very low concentrations of ammonia (2 mu M) with a wide range from 2 to 100 mu M. Also, the prospect of the device's batch fabrication is demonstrated with consistent and high stability performance. This study demonstrates a unique and stable sensing platform, capable of direct detection of ammonia concentration in human plasma for point of care applications.

Automated summary

In this study, a highly responsive FET biosensor based on tungsten trioxide thin film is fabricated to detect the physiological concentration of total ammonia in human body fluids, serving as a prognostic marker for liver disorders. The device shows reliable and accurate results for ammonia sensing, with a high response towards ammonia in human plasma. It is also capable of real-time detection of very low concentrations of ammonia, demonstrating its potential for point-of-care applications.