Ultradense Array of On-Chip Sensors for High-Throughput Electrochemical Analyses

Area of Science:

• Electrochemistry
• Biosensing
• Materials Science

Background:

• High-throughput sensors are crucial for rapid and accurate diagnostics.
• Existing electrochemical devices often lack simplicity and cost-effectiveness for large-scale use.
• Developing efficient sensor arrays is key to advancing diagnostic capabilities.

Purpose of the Study:

• To demonstrate a simple, low-cost, high-density array of vertical gold thin-film microelectrode-based sensors.
• To enable rapid and serial interrogation of multiple samples using a compact chip.
• To develop a strategy to overcome crosstalk interference and boost testing capacity.

Main Methods:

• Engineered a 3D crossbar arrangement with 16 working ultramicroelectrodes (UMEs) and 3 quasi-reference electrodes (QREs) for 48 sensors.
• Utilized chronoamperometry and square wave voltammetry with a hand-held potentiostat for analysis.
• Developed and implemented a corrective strategy involving grounding unused QRE rows to mitigate crosstalk.

Main Results:

• Successfully detected *Staphylococcus aureus* in 15 samples within 14 minutes.
• Achieved 100% accuracy in screening COVID-19 from patient serum samples using peptide-tethered immunosensors.
• Demonstrated analysis of 48 samples simultaneously within approximately 8 minutes after implementing the crosstalk correction strategy.

Conclusions:

• The developed microelectrode array offers a high-throughput, low-cost solution for electrochemical diagnostics.
• The crosstalk mitigation strategy significantly enhances the sensor array's testing capacity.
• This platform is broadly applicable for developing advanced, high-throughput ultramicroelectrode-based sensors.