Publications (Last 4)
Upasham, S., and Prasad, S*. "SLOCK (sensor for circadian clock): passive sweat-based chronobiology tracker."Lab on a Chip (2020), 20, 1947-1960
SLOCK is a human sweat based platform for circadian relevant biomarkers- cortisol and DHEA. It monitors passively expressed eccrine and apocrine sweat towards measuring and reporting cortisol and DHEA concentrations over multiple time points in humans. The sensor works on the principle of affinity based electrochemical detection. The novelty lies in the usage of a hybrid porosity platform for enhancing multibiomarker detection ability through sweat. The platform is the first demonstration of chronobiology tracking using multiple biomarkers supported by human subject-based study.
Upasham, S., Thai, K., Muthyala, R., & Prasad, S*. (2020). Flexible, low volume detection of chronobiology biomarkers from human sweat. Analyst, 145(3), 784-796 https://doi.org/10.1039/C9AN01968E
The sensor system demonstrated in this work was an affinity-based system, characterized using EIS (Electrochemical Impedance Spectroscopy).The sensor can detect cortisol and DHEA in the physiologically relevant ranges i.e. 8–200 ng ml−1 and 2–131 ng ml−1 respectively. Thus, the senor is a non-invasive, label free, cost-effective solution for tracking chronobiology for circadian diagnostics.
Upasham, S., Bhadsavle, S., & Prasad, S*. (2019). Non-invasive monitoring of a circadian relevant biomarker from easily accessible body fluids using hybrid aqueous–ionic buffer interfaces on flexible substrates. Analytical Methods, 11(9), 1180-1191.
In this paper, we demonstrate a hybrid flexible biosensor comprised of an aqueous and ionic interface integrated onto metallic gold microelectrodes for rapid and noninvasive monitoring of cortisol. We show that BMIM[BF4], a room temperature ionic liquid, can be used to modulate pH instability, as well as variations to the ionic content in the aqueous ionic buffers of sweat, urine, and saliva.
Upasham, S., Tanak, A., Jagannath, B., & Prasad, S*. (2018). Development of ultra-low volume, multi-bio fluid, cortisol sensing platform. Scientific reports, 8(1), 16745.
The development of a non-faradaic electrochemical sensor for screening across multiple bio-fluids that demonstrate the expression of cortisol using a gold microelectrode-based sensor is reported in this paper. Room temperature ionic liquid (RTIL), BMIM[BF4] was used as the buffer to modulate the electrical double layer (EDL) to enhance the electrochemical signal response of the sensor.