# Liquid-Gated Field-Effect Transistor-Based Biosensor for Uric Acid Detection

## TL;DR

This paper introduces a new biosensor using zinc oxide nanorods to detect uric acid with high sensitivity and accuracy, which could help in monitoring health conditions.

## Contribution

The study presents a novel vertical electrode FET biosensor with enhanced sensitivity and detection limits for uric acid.

## Key findings

- The biosensor achieved a sensitivity of 12.45 μA·mM−1·cm−2 with a dynamic range of 0.05–2.75 mM.
- The detection limit was calculated to be ~0.0043 mM, significantly better than traditional setups.
- The biosensor demonstrated good selectivity, stability, and applicability for serum uric acid detection.

## Abstract

Monitoring uric acid (UA) concentration is crucial for human health, enabling early detection and prevention of metabolic disorders as well as assessing renal function and overall metabolic balance. Herein, we developed a field-effect transistor (FET)-based UA biosensor using hydrothermally synthesized vertical zinc oxide (ZnO) nanorods (NRs) and uricase. The fabricated FET biosensor was tested in phosphate-buffered saline (PBS) at increasing UA concentrations to evaluate its biosensing performance. The FET biosensor yields a sensitivity of 12.45 μA·mM−1·cm−2, covering a dynamic range of 0.05–2.75 mM. The calculated detection limit was ~0.0043 mM. The improved sensing performance results in a substantial enhancement of both detection sensitivity and limit of detection compared to the traditional lateral electrode setup. Additionally, selectivity, storage stability, fabrication reproducibility, and applicability for serum UA detection were evaluated. Overall, the vertical electrode configuration of the UA biosensor has the potential to be further extended for the sensitive detection of additional biomarkers.