Flexible sensing devices integrating molecularly-imprinted polymers for the detection of 3-nitrotyrosine biomarker

Abstract

In recent years, the development of flexible and wearable devices for healthcare and biomedical applications has become an emerging technological goal, particularly with personalized medicine on the rise. As a response to the increasing demand for in-situ sensing platforms that fulfil some essential requirements like sensitivity, reproducibility and high stability, electrochemical sensors have boosted their way for innovative approaches. So, high-quality flexible sensing strategies are still a demand for local monitoring. Herein, a flexible three-electrode system was fabricated on transparent polymeric sheet substrate through physical deposition of gold as working, counter, and reference electrodes. Along the fabrication process, the electrochemical performance of these electrodes was assessed by means of cyclic voltammetry (CV) while gold adherence to the plastic material was continuously improved. Afterwards, a high-performance molecularly-imprinted sensing film inspired by natural recognition mechanism was assembled through electropolymerization of phenol monomer, in the presence of 3-nitrotyrosine (3-NT), directly on the gold surface. Under the optimized conditions, the flexible (bio)sensor platform was able to detect the presence of 3-NT over the concentration range 10 pg/mL 1 g/mL, enabling one of the lower limits of detection found in the literature (1.13 pg/mL or 24.9 pM). The obtained (bio)sensor displayed good reproducibility, stability and selectivity over the chosen interfering substances. Overall, the developed electrochemical device may serve as a flexible, miniaturized, and reliable platform, with potential to be applied in the future as wearable sensing technology.