Microfluidic Flexible Device for Real-Time Enzyme Free Uric Acid Detection

Uric Acid, an end product of purine metabolism, is a crucial biomolecule in biological fluids like blood serum and is directly associated with various cardiovascular and renal diseases. This work demonstrates the detection and quantification of uric acid using a screen-printed electrode modified with carboxylic acid functionalized multi-walled carbon nanotube (MWCNT-COOH/SPE). Here, the screen-printed electrodes are fabricated over flexible OHP sheets with a microfluidic reservoir. Surface morphological analysis of MWCNT-COOH/SPE is done through microscopic characterization. Differential pulse voltammetry (DPV) and Cyclic Voltammetry (CV) techniques are used for the electrochemical characterization of the device. The device is tested for a linear range of uric acid from 10 μM to 1000 μM and the limit of detection (LoD) and limit of quantification (LoQ) obtained are 4.29 μM and 14.31 μM, respectively. Further, the real sample analysis using blood serum substantiated the applicability and feasibility of the sensor. This device demonstrated a sensitive, enzyme-less sensing of uric acid with a potential to be used in bedside analysis.