Chinese Scientists Develop New System to Enable Needle-Free Blood Sodium Measurement

Chinese scientists have made a significant breakthrough in the field of needle-free diagnostics by developing a novel terahertz optoacoustic system. This system overcomes the interference caused by water and enables real-time measurement of blood sodium levels in live mice without the need for blood sampling or labeling. Preliminary human trials have also demonstrated its potential for clinical applications.

This research findings were made by Professor Tian Zhen, Associate Professor Li Jiao, and Ph.D. student Yao Yixin from the School of Precision Instrument and Optoelectronics Engineering of Tianjin University.

Terahertz radiation falls between microwaves and the mid-infrared region of the electromagnetic spectrum. It is ideal for non-invasive medical diagnostics because it is low-energy and non-harmful to tissues, scatters less than near-infrared and visible light and is sensitive to structural and functional biological changes.

However, the strong absorption of terahertz radiation by water has long posed two major challenges for its biomedical applications: how to eliminate the interference from water molecules in complex biological samples and how to enable penetration through thick tissue to achieve in vivo detection.

Terahertz Optoacoustic System enables in vivo, label-free sodium ion detection.

Accurate measurement of blood sodium is essential for diagnosing and managing conditions such as dehydration, kidney disease and certain neurological and endocrine disorders. The research team from Tianjin University developed an optoacoustic (OA) terahertz spectroscopy system that can be used for long-term, non-invasive monitoring of blood sodium levels.

“This system generates ultrasound waves, which are captured by an ultrasonic transducer. As the sample absorbs terahertz waves, it vibrates the sodium ions connected to water molecules in the blood, creating ultrasound waves that are detected with an ultrasonic transducer. This optoacoustic detection technique effectively converts absorbed terahertz energy into sound waves, significantly reducing the interference caused by water and enabling long-term, non-invasive monitoring of blood sodium levels in live mice. Early human volunteer trials also showed promising results.” Said Professor Tian Zhen from Tianjin University.

“The broader significance of this work extends far beyond blood sodium detection. This technology has the capability to identify various biomolecules—including sugars, proteins, and enzymes—by recognizing their unique terahertz absorption signatures.” Said Associate Professor Li Jiao from Tianjin University.

By: Sun Xiaofang