Publication date: Jan 20, 2024
Multiplexing is a valuable strategy to boost throughput and improve clinical accuracy. Exploiting the vertical, meshed design of reproducible and low-cost ultra-dense electrochemical chips, the unprecedented single-response multiplexing of typical label-free biosensors is reported. Using a cheap, handheld one-channel workstation and a single redox probe, i. e., ferro/ferricyanide, the recognition events taking place on two spatially resolved locations of the same working electrode can be tracked along a single voltammetry scan by collecting the electrochemical signatures of the probe in relation to different quasi-reference electrodes, Au (0. 0 V) and Ag/AgCl ink (+0. 2 V). This spatial isolation prevents crosstalk between the redox tags and interferences over functionalization and binding steps, representing an advantage over the existing non-spatially resolved single-response multiplex strategies. As proof of concept, peptide-tethered immunosensors are demonstrated to provide the duplex detection of COVID-19 antibodies from distinct samples, thereby doubling the throughput while achieving 100% accuracy in serum samples. We envision the approach to enable broad applications in high-throughput and multi-analyte platforms, as it can be tailored to other biosensing devices and formats. This article is protected by copyright. All rights reserved.
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