Ascorbic Acid Rejection Characteristics of Modified Platinum Electrodes: A Shelf Life Investigation

Chemosensors

Andrea M. Wynne²  Niall J. Finnerty¹ 

[1] Sensors Development Unit and Neurochemistry Research Unit, BioAnalytics Laboratory, Department of Chemistry, Maynooth University, Co. Kildare, Ireland; E-Mail

关键词: Ascorbic acid;    Nafion^®;    Poly-o-phenylenediamine;    membrane integrity;    storage;   

DOI  :  10.3390/chemosensors3020055

来源: mdpi

【 摘 要 】

Ascorbic acid (AA) is the principle interferent present in brain extracellular fluid that can inhibit the ability of electrochemical sensors to selectively detect a particular analyte of interest. Considerable efforts have been made in recent times to develop highly selective membrane coatings to counteract the drawbacks associated with AA interference during in vivo monitoring. The primary objective of the work described within was to investigate the long term effect of storing such selective membranes, i.e., Nafion^® and Poly-o-phenylenediamine (PPD) under different conditions and how exposing them to repeated calibration protocols compromises the membranes ability to reject AA. Four different modified platinum (Pt) electrodes, Pt-PPD, Pt-Nafion^® (5/2), Pt-Nafion^® (1/2)-PPD, and Pt-Nafion^® (2/1)-PPD, stored at 4 °C demonstrated deterioration of the polymers integrity when exposed to repeated calibrations. On the contrary, exposing the same four electrode types to single calibrations confirmed excellent retention of AA rejection characteristics. Pt-PPD electrodes were then exposed to varying storage conditions and calibrated against AA on day 1, day 56 and day 168. Storing the Pt-PPD electrodes at 4 °C/N₂ saturated glass container demonstrated retention of AA rejection characteristics after day 168. These results have clearly elucidated the optimum storage conditions for Pt-Nafion^® and Pt-PPD modified electrodes.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.