Scalable Multiplexed Electrochemical Aptasensor Enabled by Chitosan for Heavy Metal Ion Detection: Advancing Electrode Functionalization and Reusability
Year: 2026
Type: preprint
Abstract: The rapid and reliable detection of heavy metal ions in water remains a critical challenge for environmental monitoring and public health protection. While recent advances in aptamer-based electrochemical sensors for heavy metal detection emphasize miniaturization and improved electrode modification techniques to achieve higher sensitivity, striking a balance among the sensor's analytical performance, ease of fabrication, and scalability remains a major challenge, often resulting in trade-offs between sensitivity and scalability. Herein, we have developed a sensitive, multi-analyte aptamer-based electrochemical sensor by modifying micro structured electrodes with chitosan, which adheres to their inherent functional groups, thereby simplifying sensor preparation. The target-specific aptamers are immobilized via glutaraldehyde-mediated crosslinking chemistry. Using a differential pulse voltammetry measurement technique the sensitivities of the sensor for specific heavy metals was found to be 21.7, 15.18, and 9.25 ΔI per decade change in concentration per unit area for Pb(II), As(III), and Cd(II), respectively. The limit of detection for the developed sensor is observed to be 1.03 ng/L for Pb(II), 0.45 ng/L for As(III), and 3.03 ng/L for Cd(II) in water. Further, the sensor's reusability has been analysed using a chelation mechanism in combination with potential stripping voltammetry. The sensor was effectively regenerated and reused across four consecutive cycles, thereby reducing the cost per test.
Source: ChemRxiv
Institutions: University College Cork, Tyndall National Institute
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Award: G381538396
OpenAlex ID: W7214586025