Determination of Ascorbic Acid in Commercial Tablets Using Pencil Drawn Electrochemical Paper-based Analytical Devices

Abstract

This study describes the use of electrochemical paper-based analytical devices (ePADs) drawn with graphite pencil for the determination of ascorbic acid (AA) in commercial tablets. ePADs were fabricated using vegetal paper and graphite pencil. First, the three-electrode electrochemical cell drawn using a graphical software and toner lines were laser printed on the vegetal paper surface to delimit the electrode areas. Then, the electrode regions were manually painted with graphite pencil. Afterwards, the pseudo-reference electrode was defined with the deposition of silver ink over the graphite surface. Cyclic voltammetry and square wave voltammetry (SWV) experiments were performed to optimize the electroanalytical parameters as well as to quantitatively determine the AA concentration in two commercial tables. ePADs exhibited linear behavior for a concentration range between 0.5 and 3.0 mmol L. The achieved limit of detection and sensitivity were 70 μmol L and 0.47 μA/mmol L, respectively. The AA concentration levels found by SWV experiments in both Cenevit and Energil C were 2.80 ± 0.02 and 3.10 ± 0.01 mmol L, respectively. The accuracy of the proposed devices was investigated through recovery experiments in three concentration levels and it presented values between 95 and 115%.

Nano-Cu Modified Cu and Nano-Cu Modified Graphite Electrodes for Chemical Oxygen Demand Sensors

“…22 On the other hand, graphite is cheap, simple, and a well-known carbon electrode. 23 The characteristic of the electrochemical sensors was assessed using standard reagents of glycine and glucose to evaluate COD value. 15 Validation performed by conventional measurements of COD showed comparable results with the prepared electrodes, indicating that the prepared electrodes are promising for COD sensors.…”

A Glassy Carbon Electrode Modified with Molybdenite and Ag Nanoparticle Composite for Selectively Sensing of Ascorbic Acid

“…3 Electrochemical techniques are the most common and easy approach to the quantitative detection of small biomolecules owing to their high sensitivity, fast response and low expense. Numerous materials, such as noble metal nanoparticles, 4 metal oxide, 5,6 CdS quantum dots, 7 and carbon materials 8,9 have been used to modify electrodes to realize the electrochemical detection of AA. Because the electrochemical oxidation peak potentials for DA, UA and AA are close, research has focused on how to selectively detect of these compounds effectively.…”

Nanoparticle-based Point of Care Immunoassays for in vitro Biomedical Diagnostics

“…metabolic disorders, different types of renal disorders depending upon the concentration of protein. [13][14][15][16] To address the diagnostics hurdles, and to enhance the sensitivity of the assay, nanoparticles-based immunoassays have been reported, which rely on the unique properties of nanoparticles and have improved detection limit up to 1000 times. [17][18][19][20]…”