Electrochromic Sensor Augmented with Machine Learning for Enzyme-Free Analysis of Antioxidants

Abstract

Our study presents an electrochromic sensor that operates without the need for enzymes or multiple oxidant reagents. This sensor is augmented with machine learning algorithms, enabling the identification, classification, and prediction of six different antioxidants with high accuracy. We utilized polyaniline (PANI), Prussian blue (PB), and copper−Prussian blue analogues (Cu-PBA) at their respective oxidation states as electrochromic materials (ECMs). By designing three readout channels with these materials, we were able to achieve visual detection of antioxidants without relying on traditional "lock and key" specific interactions. Our sensing approach is based on the direct electrochemical reactions between oxidized electrochromic materials (ECMs ox ) as electron acceptors and various antioxidants, which act as electron donors. This interaction generates unique fingerprint patterns by switching the ECMs ox to reduced electrochromic materials (ECMs red ), causing their colors to change. Through the application of density functional theory (DFT), we demonstrated the molecular-level basis for the distinct multicolor patterns. Additionally, machine learning algorithms were employed to correlate the optical patterns with RGB data, enabling complex data analysis and the prediction of unknown samples. To demonstrate the practical applications of our design, we successfully used the EC sensor to diagnose antioxidants in serum samples, indicating its potential for the on-site monitoring of antioxidant-related diseases. This advancement holds promise for various applications, including the real-time monitoring of antioxidant levels in biological samples, the early diagnosis of antioxidant-related diseases, and personalized medicine. Furthermore, the success of our electrochromic sensor design highlights the potential for exploring similar strategies in the development of sensors for diverse analytes, showcasing the versatility and adaptability of this approach.

Fabrication strategies for metallic nanowire flexible transparent electrodes with high uniformity

“…Electrochromic devices (ECDs), with the ability to reversibly adjust optical properties, have found widespread applications in various fields, such as smart windows for buildings, 161,162 displays, 163–165 and sensing, 166–168 attracting considerable attention from both industry and academia. These devices typically consist of a five-layer structure, with top and bottom layers comprised of transparent electrodes made of transparent substrates and conductive layers, respectively, onto which electrochromic layers and counter electrode layers are deposited to achieve color-changing functionality and ion storage during this process.…”