Small Tech, Big Changes
Xuewei Wang, Ph.D., Department of Chemistry
Sometimes the biggest medical advances come in the smallest packages. Just ask Xuewei Wang, an associate professor in the Department of Chemistry. Wang develops chemical sensors, small devices designed to measure a specific chemical in body fluids, to help with health monitoring and disease diagnosis outside of hospital settings – technological innovations that could revolutionize the detection and healing process. Wang was recently awarded the VCU Outstanding Early Career Faculty Award.
What led you to this work? Why did this interest you?
As a child, I loved drawing beautiful pictures and writing elegant Chinese characters. When I started working on chemical sensors in graduate school – devices used to measure a specific chemical – I realized that designing sensors was like creating art, and I found great joy in this process.
Creating an effective chemical sensor requires elegant chemistry, design and engineering. The chemistry involves how the sensor recognizes and interacts exclusively with the target chemical. The design aspect focuses on how this interaction with the target chemical changes into a detectable signal, such as voltage, current, color or fluorescence. The engineering element involves fabricating the device to meet specific application needs. The elegance of these three facets continues to fascinate me.
What makes developing chemical sensors challenging, especially ones that are portable, wearable, implantable and/or microfluidic?
In analytical laboratories, larger instruments can be used, and samples can be tested using multiple steps. However, sensors often need to work directly in real samples, such as whole blood, without any processing steps. They must be highly selective and match the target chemical levels in real samples. Sometimes the analyte is present in very low concentrations, or the sensor needs to detect tiny changes in concentration. Chemical sensors also must be fast in response and sometimes need to remain stable during continuous use over days or weeks.
Additionally, they must be affordable and easy to use, especially for portable, wearable, and implantable sensors used by end users rather than health care professionals. In medical diagnostics, the reliability of chemical sensors is especially crucial. It is hard for a small device to do such a big job without errors.
How will the development of these sensors change health care and patient lives?
Currently, most chemical measurements are performed in laboratories far from patients. The frequency of such tests is very limited, and it often takes a long time to provide results to physicians and patients. The creation of at-home sensors would help for the detection and management of chronic diseases and negate some of those hurdles. For example, glucose meters and continuous glucose monitors have revolutionized diabetes management. Our focus is on a group of analytes called electrolytes, such as potassium, sodium, calcium, magnesium and chloride ions. Abnormal blood electrolyte levels can indicate many kidney, heart, parathyroid and liver diseases, and close tracking of blood electrolyte levels is crucial when treating these chronic diseases. Therefore, there is a significant need for at-home monitoring of electrolytes. Currently, no products are available for this purpose, and we are very passionate about pursuing this direction.
We also focus on critically ill patients, such as those in ICU settings. These patients would benefit from continuous monitoring of critical care biomarkers like lactate, glucose, gases and electrolytes. We are developing microfluidic technology for continuous monitoring of multiple blood parameters at the bedside. This real- time information will allow physicians to implement the best interventions without delay. Current blood draws and tests are performed at intervals of at least a few hours, which is too infrequent for ICU patients whose conditions change rapidly. We are hopeful that we can transform patient monitoring with these new sensor technologies.