Spray-Capillary: An Electrospray-Assisted Device for Quantitative Ultralow-Volume Sample Handling

Area of Science:

• Analytical Chemistry
• Biotechnology
• Biophysics

Background:

• Microsampling techniques are crucial for analyzing complex biological systems from low-volume samples.
• Current methods for proteomic and metabolomic analysis of low-volume samples face challenges in simplicity, efficiency, and reproducibility.

Purpose of the Study:

• To develop and evaluate a novel electrospray-assisted device, Spray-Capillary, for quantitative extraction of ultralow-volume samples.
• To assess the precision and accuracy of the Spray-Capillary device for microsampling applications.

Main Methods:

• Development of an electrospray-assisted device (Spray-Capillary) utilizing a chemically etched capillary tip and conductive sheath flow.
• Quantitative evaluation of sample injection volumes by varying electrospray voltage, capillary inner diameter, and column length.
• Direct coupling of the Spray-Capillary device with capillary zone electrophoresis (CZE) for sample separation.

Main Results:

• The Spray-Capillary device achieved stable electrospray, enabling quantitative sample uptake.
• Demonstrated reproducible and accurate microsampling with low injection flow rates (down to 15 pL/s).
• Successful direct coupling with capillary zone electrophoresis for integrated separation.

Conclusions:

• Spray-Capillary offers a simple, efficient, and reproducible microsampling solution for ultralow-volume biological samples.
• The device holds significant potential for advancing high-throughput quantitative omics analysis.
• This technology can overcome existing limitations in analyzing minute biological sample volumes.