(Invited) Portable Iron Screening System for Point-of-Care Iron Status Determination

Abstract

Women undergoing basic military training are particularly susceptible to iron deficiency (ID) and iron deficiency anemia (IDA). Symptoms of iron depletion, such as fatigue and reduced cognitive ability, have raised concerns over the effect of unchecked iron deficiencies on United States military preparedness. Therefore, screening recruits for iron status is vital to the health and safety of the people serving our country. Currently, there exists no robust point-of-care method for rapid iron status determination. Here we present a point-of-care iron status determination system, which can rapidly determine iron status based on a panel of markers. The methodology used for determination of iron status is based on immunosensor measurement from human plasma samples by means of impedance analysis. Antibodies respective to soluble transferrin receptor (sTfR), transferrin, and ferritin were linked to the electrode surface using dithiobis succinimidyl propionate (DSP). The transferrin sensor exhibited linear calibration curve for concentrations ranging from 0.5-5.5 mg/mL transferrin protein. With given linearity, the transferrin levels detected in all tested plasma samples were found to be 1.5 - 1.7 mg/mL respectively, that fall within expected normal reference ranges. The transferrin clinical threshold for ID and IDA is >4.0mg/mL. The sTfR sensor was capable of measuring sTfR in PBS between 0.1 and 3.2 mg/L. The clinical threshold for ID and IDA is >3.6 mg/L of sTfR. The sTfR levels detected in all tested plasma samples were found to be 1.8 - 4.4mg/L respectively. The concentrations measured by the developed sensors were in excellent agreement with ELISA. Further improvements will be performed with screen printed array gold electrodes for multiplex sensing of all the biomarkers. These sensors will be integrated into a cartridge, and along with electronic hardware and software for interpreting the results, will be a fully functional system for the rapid determination of ID and IDA.