Our Mission

Our group is currently working at the interface of chemistry, biology, and engineering to develop and apply novel nano-scale probes for biological measurements.

Ultimately, our goal is to use the probes to image specific chemical processes occurring deep in the body (brain, central and peripheral nervous system, and circulatory system), in real-time.

Central Nervous System

In response to recent advances in MRI technology, we have developed a novel probe for real-time mapping of acetylcholine in the brain. Enzymatic hydrolysis of acetylcholine causes deprotonation of the co-localized contrast agent, altering the measurable relaxivities of the sensor to generate a readable image of the choline pathway.

Peripheral Nervous System

Currently, it is difficult to quantify the dynamics of small molecules in the brain in real-time and connect those measurements to the overall picture of brain function. Here, we developed a fluorescence-based DNA dendrimer nanosensor for in vivo detection of acetylcholine (a key neurotransmitter). Our sensor is designed to provide high spatial and temporal resolution through the use of ratiometric pH sensing, in response to enzymatic acetylcholine hydrolysis.

Circulatory System

Affective drug dosage requirements vary between patients and can be difficult to determine due to rapid clearance of sensors. Here we have designed a salt sensor housed within the membrane of a red blood cell. These RBC ghosts can circulate longer in the blood stream while optical detection of the sensors occurs at superficial veins.

Immune System

Real-time monitoring of protein levels in the body is essential for understanding disease and ensuring proper therapeutic doses. Here, we demonstrate a DNA-based nanosensor for the photoacoustic (PA) detection of interferon gamma (IFN╬│), a clinically relevant cytokine. Upon receptor binding, the structure bends to induce phthalocyanine (Pc) J-aggregate dye stacking, resulting in a quantifiable increase in PA signal.

The Clark Lab
Arizona State University
School of Biological and Health Systems Engineering
ASU Engineering Center, Tempe, AZ 85281