Disposable paper-based electrochemical sensor utilizing inkjet-printed Polyaniline modified screen-printed carbon electrode for Ascorbic acid detection

In this work, a new paper-based electrochemical sensor is developed as a low-cost and disposable point-of-care device for pre-screening purpose. Electrodes of this new sensor are fabricated using two printing techniques, i.e. screen-printing for base material and inkjet-printing for modifying functional material, and the performance of fabricated sensors for Ascorbic acid detection is demonstrated. The paper-based device consists of three electrodes including Polyaniline (PANI) modified Screen-Printed Carbon Electrode (SPCE) as working electrode and two bare SPCEs as reference and counter electrodes. Three SPCEs are initially screen-printed on a filter paper, and PANI is consecutively inkjet-printed on the designated working SPCE. Its electrochemical performances are systematically investigated towards Ascorbic acid using Cyclic Voltammetry (CV) with different Acetate buffer pHs and numbers of printed-PANI layers. The CV results show that the optimal buffer pH and number of PANI layers are 4.0–5.0 and 5, respectively. Consequently, real-time detection of Ascorbic acid concentration is performed using Chronoamperometry technique under the optimal conditions from previous CV studies. From the results, the sensor exhibits a good sensitivity of 17.7 μA/mM and a moderately low limit-of-detection of 30 ± 3 μM in a concentration range of 30–270 μM. According to cost versus performance, the utilization of paper-based sensor with inkjet-printed PANI modified SCPE is an alternative choice for low-cost and disposable point-of-care applications.