Development of HRP-assisted rGO-FET biosensors for high-precision measurement of serological steroid hormones

Background: Sarcopenia, which is associated with many pathways and molecular mechanisms, not only deteriorates the quality of life in old age but is also linked to various diseases. The ratio between cortisol and dehydroepiandrosterone sulfate (DHEAS) was utilized as a candidate method to diagnose sarcopenia. The hormones can fluctuate in concentration throughout the day, so monitoring the ratio between the two hormones is necessary. Therefore, accurate sensors are essential to measure each cortisol and DHEAS in human-derived biofluids such as blood and plasma.

Results: An electric-based biosensor that does not require a complicated manufacturing process was utilized using reduced graphene oxide (rGO) and improves sensitivity and selectivity by using HRP to monitor hormone changes in the human body, especially in human plasma. To prove the performance of the proposed hormone-monitoring sensor, we performed quantitative detection of cortisol and DHEAS in the buffer solution and human plasma with pre/absence HRP binding. Additionally, the selectivity of the sensor was verified by the detection of cortisol and DHEAS constitutional isomers, such as estradiol, dexamethasone, and cortisone. Furthermore, the quantitative detection results of cortisol and DHEAS in buffer solution were used to calculate the concentrations of cortisol and DHEAS from human plasma results.

Significance: This analysis defined the detection accuracy compared with the normal human range of certain hormones. The accuracy of the analyzed data was up to 99 %, thus suggesting that the presented HRP replacement detection method utilizing the rGO-FET biosensor could be used for quantitative hormone measurement as well as sarcopenia monitoring.