Ultrasensitive Electrical Detection of Follicle-Stimulating Hormone Using a Functionalized Silicon Nanowire Transistor Chemosensor.

The follicle-stimulating hormone (FSH) is a hormone that belongs to a family of glycoprotein hormones. Determination of FSH can help in interpreting various factors that include physiology of the reproductive system, fertility maintenance, and identification or treatment of reproductive disorders. Sialic acids are derivatives of neuraminic acids with negative charges, present at the end of the sugar chains and further linked to the cell surfaces and glycoproteins. The direct measurement of FSH in a human body can be recorded by developing a sensor probe that responds particularly to sialic acids over the other hormones. However, existing diagnostic methods still suffer from many difficulties in terms of complicated handling techniques, expensive instrumentation, etc. Development of accurate, rapid, and low-cost FSH detection chemosensors is important to meet these demands. Herein, we utilized a novel sensing method for accurate and fast FSH detection using a metal-oxide semiconductor silicon nanowire field effect transistor (SiNW-FET) device. This is the first report to demonstrate the boronic acid-functionalized SiNW-FET device in FSH detection. FSH detection has been successfully determined using an assay buffer solution with 0.72 fM detection limit as well as using 20% serum with 1.1. fM detection limit. We also investigated the specificity with other gonadotropins/glycosylated serum proteins. The current measurements on FSH concentrations at different time intervals were also studied. The sensitive, cheap, and miniaturized SiNW-FET device can serve as an effective sensing approach for rapid screening of FSH and menopause diagnosis.