Miniaturized electrochemical platform with ink-jetted electrodes for multiplexed and interference mitigated biochemical sensing

Development of miniaturized devices has yielded many advantages, such as automation, portability and robustness. Out of several detection schemes, electrochemical sensing is the preferred choice due to its selectivity, accuracy and repeatability. In the present work, a miniaturized three-electrode electrochemical device has been fabricated on a glass substrate using inkjet printing of carbon conductive inks for sensing of xanthine (X), hypoxanthine (HX) and uric acid (UA). Hereby, the electroactive graphitized mesoporous carbon modified on conductive carbon paste acted as working electrode. The electrochemical behaviors of these purines were tested using cyclic voltammetry and squarewave voltammetry (SWV). The morphology and structural properties were characterized using scanning electron microscopy. Under the optimized conditions, the linear ranges for X, HX and UA were 2-12, 10-20 and 1-7 mu M, respectively. The limit of detections for all these purines are 3.33, 9.99 and 0.01 mu M for X, HX and UA, respectively. The developed platform was also utilized for interference with other co-existing bio-chemicals manifesting negligible interference. Further, the platform was successfully tested with human serum samples for X, HX and UA detection. Conclusively, the modified electrodes showed excellent reproducibility and specificity applicable to real samples.