Development of a Point-of-Care device to quantify serum zinc to aid the diagnosis and follow-up of pediatric septic shock

In the Unites States Pediatric septic shock is a major health problem with about 42,000 cases per y ear and a mortality rate of about 10% [1]. Studies have indicated that children with pediatric septic shock have demonstrated critically low levels of serum z inc (Zn) and supplementation of Zn is being suggested as a therapeutic strategy. However, to protect patient safety, it is v ital that Z n levels be monitored during supplementation to insure the Zn concentration levels remain at or near physiologic normal levels. Currently Atomic Absorption Spectroscopy (AAS) is used to quantify Zn levels in serum samples. Unfortunately, AAS frequently involves sending serum samples to external laboratory facilities which yields measurement turnaround time that range from hours to days. Thus, timely monitoring of Zn levels is critical to preventing over supplementation that could result in critical conditions such as heavy metal (Zn) toxicity. This paper reports on the development of a Point-of-Care device for rap id electrochemical measurement of Zn. The prototype device is able to accurately quantify Zn in serum with a turn-around time of about 30 minutes. The devices is based on a three electrode sensor which uses Anodic stripping voltammetry (ASV) for sensing Zn levels. The ASV electrode sensor is read using a reader that has be en developed using commercially available embedded system components and custom analog circuitry.