The development of advanced and powerful detection techniques to characterize as many endocrine disruptors as possible with high sensitivity in the environment is still a challenge, but with great demand. Environmental estrogens (EEs) as typical endocrine disruptors have been listed as one of the global environmental problems that must be addressed through the international cooperation of the United Nations. They are structurally diverse compounds that can interact with nuclear estrogen receptors and pose significant risks to the environment and human health.
In a new article published in Light Science & Application, a team of photonics and environmental scientists led by Prof. Tuan Guo of Jinan University and Dr. Xiaohong Zhou of Tsinghua University developed an easy-to-implement plasmonic fiber optic biosensor platform for ultra-sensitive detection of estrogenic endocrine disruptors. The platform is based on a gold-coated, highly inclined fiber Bragg grating that excites high-density spectral ridges with a narrow cladding mode that overlap with the wider absorption of the surface plasmon to enable highly accurate interrogation and thus ultra-sensitive monitoring of refractive index changes on the fiber surface. Using estrogen receptors as a model, they use molecular dynamics to design an estradiol-streptavidin conjugate that converts the specific recognition of environmental estrogens by estrogen receptors into a surface-based affinity bioassay for proteins. The ultrasensitive platform with conjugate-induced amplification biosensor approach enables the subsequent detection of EEs down to a concentration of 1.5 ng l-1 estradiol equivalent. This is the lowest limit of detection for any evidence for estrogen receptors reported to date.
In addition, the compact size, flexible shape and remote control of the fiber-integrated plasmonic biosensor pave the way for the detection of other endocrine disruptors with ultra-high sensitivity and in various hard-to-reach areas, with the potential to revolutionize environmental and health monitoring. The biosensor can, for example, be used for the continuous detection of endocrine disruptors in the field and thus meets the urgently required demand for timely monitoring of the state of the environment. The integration of such a fiber biosensor with an injection needle would, on the other hand, enable measurements similar to those of portable on-site and field analyzes in health monitoring, even in vivo.
Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, Chinese Academy of Sciences
Liu, L., et al. (2021) Ultra-sensitive detection of endocrine disruptors via superfine plasmonic spectral ridges. Light: Science & Applications. doi.org/10.1038/s41377-021-00618-2.