An automatic immuno-microfluidic system integrating electrospun polystyrene microfibrous reactors for rapid detection of salivary cortisol

Yecan Wang; Hiroshi Murakami; Toshihiro Kasama; Shigenobu Mitsuzawa; Satoru Shinkawa; Ryo Miyake; Madoka Takai

doi:10.1016/j.isci.2023.107820

An automatic immuno-microfluidic system integrating electrospun polystyrene microfibrous reactors for rapid detection of salivary cortisol

iScience. 2023 Sep 6;26(10):107820. doi: 10.1016/j.isci.2023.107820. eCollection 2023 Oct 20.

Authors

Yecan Wang¹, Hiroshi Murakami¹, Toshihiro Kasama¹, Shigenobu Mitsuzawa², Satoru Shinkawa², Ryo Miyake¹, Madoka Takai¹

Affiliations

¹ Graduate School of Bioengineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo City, Tokyo 113-8654, Japan.
² Honda Motor Co., Ltd, 8-1 Honcho, Wako, Saitama 351-0114, Japan.

Abstract

Conventional competitive enzyme-linked immunosorbent assay (ELISA) to measure the cortisol level in body fluid consumes a large amount of time, owing to complicated operations involved and requirement for precise control of reagent addition. We developed an automatic microfluidic system to detect salivary cortisol rapidly, and an electrospun polystyrene (PS) microfiber-based reactor providing considerable binding sites for antibody immobilization, thus resolving the time limitations of competitive ELISA. Cortisol sample, horseradish peroxidase (HRP)-conjugated cortisol, and 3,3',5,5'-tetramethylbenzidine (TMB) substrate were delivered to the PS reactor from containers in sequence by pumps automatically. The color variation due to oxidized TMB complex reflects the cortisol concentration level measured using an RGB phototransistor. In addition, the entire procedure from sample introduction to obtaining the photocurrent took only 15 min. This system can be implemented to quantify cortisol from 0.37 ng/mL to 30 ng/mL, and the limit of detection was estimated at 0.37 ng/mL.

Keywords: Analytical chemistry applications; Diagnostic technique in health technology.