Gold star–carbon nanotube composite for analysing preeclampsia during pregnancy

Preeclampsia is the condition identified with a high blood pressure and protein in the urine during the period of pregnancy, which affects 6–8% of pregnant women after 20 weeks of pregnancy. Untreated preeclampsia causes serious health issues to the mother and baby. Diagnosing followed by treating preeclampsia with a suitable biomarker is mandatory for healthy delivery. Cortisol, the steroid hormone secreted from the adrenal glands, helps to regulate various physiological processes, such as immune response, metabolism and blood pressure. In this research, cortisol was quantified on carbon nanotube (CNT)-modified interdigitated electrode sensor. Aptamer, an artificial antibody having a high binding affinity to the target, was utilized for quantifying the cortisol. Further, to enhance the detection, gold star was conjugated with aptamer and immobilized on CNT. The limit of cortisol detection was found in the range of 7–15 pg/mL. Selective detection of cortisol was analysed with two different hormones, namely norepinephrine and progesterone, and it was found that aptamer recognizes only cortisol. This strategy with the nanocomposite helps in diagnosing preeclampsia during the period of pregnancy.