Toward "Receive-Only" Nuclear Magnetic Resonance Complementary Metal-Oxide-Semiconductor Microcoil Arrays for...

Area of Science:

• Biochemistry
• Analytical Chemistry
• Environmental Science

Background:

• Daphnia magna neonates and eggs are sensitive life stages for toxicological studies.
• Nuclear Magnetic Resonance (NMR) spectroscopy offers biochemical insights but struggles with small, mass-limited samples.
• Microcoil NMR enhances sensitivity but faces throughput limitations due to experiment duration and cost.

Purpose of the Study:

• To develop a cost-effective and high-throughput NMR method for analyzing mass-limited biological samples, specifically Daphnia magna eggs.
• To overcome practical challenges associated with microcoil arrays, such as expensive receivers and limited space.
• To improve signal-to-noise ratio (SNR) and reduce acquisition times for NMR experiments on small samples.

Main Methods:

• Utilized "receive-only" planar complementary metal-oxide-semiconductor (CMOS) microcoils with external volume coil excitation.
• Employed steady-state free precession experiments to further enhance SNR and reduce acquisition time.
• Adapted an inexpensive software-defined radio board as a low-cost NMR receiver for a three-coil array.

Main Results:

• Achieved a 70% SNR boost by using external excitation with planar CMOS microcoils.
• Improved SNR by at least 2.5-fold using steady-state free precession, reducing experiment time.
• Demonstrated concurrent analysis of three Daphnia magna eggs using a cost-effective microcoil array.

Conclusions:

• Microcoil arrays, particularly with "receive-only" designs and affordable receivers, offer a promising solution for high-throughput NMR analysis of mass-limited samples.
• This approach can significantly advance toxicological studies by enabling concurrent analysis of control and exposed cohorts, minimizing variability.
• The developed method holds potential for broader applications in studying other small biological samples and chemical analyses.