Fig. 3: OFET for detection of sFlt-1. Bottom Left.
From: Biomarkers and point of care screening approaches for the management of preeclampsia
A schematic illustrating the structure of a Polyisoindigo-based organic semiconductor (pII2T-Si, chemical structure provided). pII2T-Si encapsulated the two drain and source Au electrode by spin coating with silicon oxide as the dielectric layer and silicon as the Gate. Top Left: Compared to typical FET devices, OFET combines the idea of ELISA. OEFT sensor functionalized with specific antibodies will capture sFlt-1. Sequentially, the biotinylated detector antibodies will bind on the top to form a sandwich complex. With the addition of streptavidin-conjugated glucose oxidase, glucose will be converted into gluconic acid. The more the sFlt-1 are captured, more gluconic acid formed to decrease the pH value as more glucose oxidase are available. The decrease in pH value of the solution will further increase the current flow of the device which can be an indicator corresponding to the amount of sFlt-1 captured. Au electrode will be the ‘source’ and ‘drain’ for signal transduction. Bottom Right: a graph showing normalized intensity versus time along with various addition of different concentrations of sFlt-1 (0–40 ng mL−1), demonstrating a successful real-time quantification of sFlt-1 levels in the plasma. Top Right: Organic Field-effect transistors developed for the detection of sFlt-1 utilize an antibody based catalytic sandwich-assay to quantify sFlt-1 across a range of 1.25–10 ng/mL121.
