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Lookup NU author(s): Dr Keng Wooi NgORCiD
This is the authors' accepted manuscript of an article that has been published in its final definitive form by American Chemical Society, 2019.
For re-use rights please refer to the publisher's terms and conditions.
Minimally invasive, reliable and low-cost in vivo biosensors that enable real-time detection and monitoring of clinically relevant molecules and biomarkers can significantly improve patient health care. Microneedle array (MNA)-based electrochemical sensors offer exciting prospects in this respect, as they can sample directly from the skin. However, their acceptability is dependent on developing a highly scalable and cost-effective fabrication strategy. In this work, we evaluated the potential for poly(lactic acid)/carboxyl-multiwalled carbon nanotube (PLA/f-MWCNT) composites to be developed into MNAs and their effectiveness for dermal biosensing. Our results show that MNAs are easily made from solvent-cast nanocomposite films by micromolding. A maximum carbon nanotube (CNT) loading of 6 wt % was attained with the current fabrication method. The MNAs were mechanically robust, being able to withstand axial forces up to 4 times higher than necessary for skin insertion. Electrochemical characterization of these MNAs by differential pulse voltammetry (DPV) produced a linear current response toward ascorbic acid, with a limit of detection of 180 μM. In situ electrochemical performance was assessed by DPV measurements in ex vivo porcine skin. This showed active changes characterized by two oxidative peaks at 0.23 and 0.69 V, as a result of the diffusion of phosphate-buffered saline. The diagnostic potential of this waveform was further evaluated through a burn wound model. This showed an attenuated oxidative response at 0.69 V. Importantly, the impact of the burn could be measured at progressive distances from the burn site. Overall, alongside the scalable fabrication strategy, the DPV results promise efficient electrochemical biosensors based on CNT nanocomposite MNAs.
Author(s): Skaria E, Patel BA, Flint MS, Ng KW
Publication type: Article
Publication status: Published
Journal: Analytical Chemistry
Print publication date: 02/04/2019
Online publication date: 14/03/2019
Acceptance date: 14/03/2019
Date deposited: 20/03/2019
ISSN (print): 0003-2700
ISSN (electronic): 1520-6882
Publisher: American Chemical Society
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