Ultrasensitive Screening of Endocrine-Disrupting Chemicals Using a Surface Plasmon Resonance Biosensor with Polarization-Compensated Laser Heterodyne Feedback

Abstract

Developing an ultrasensitive and reliable device for continuous monitoring of various endocrine-disrupting chemicals (EDCs) is in high demand, yet it remains a significant challenge. Traditional label-free surface plasmon resonance (SPR) sensing relies on the interaction of the surface plasmon wave and the sensing liquid via intensity modulation, endowed with simple structure and easy-to-miniaturization, however suffering from inferior sensitivity and stability. Here, we propose a novel optical structure in which the frequency-shifted light of different polarization returned to the laser cavity to stimulate laser heterodyne feedback interferometry (LHFI), hence amplifying the reflectivity change caused by the refractive index (RI) variations on the gold-coated SPR chip surface, and the s-polarized light could be further used as a reference to compensate for the noise of the LHFI-amplified SPR system, resulting in nearly three orders of magnitude enhancement of the RI sensing resolution (5.9 × 10 −8 RIU) compared to the original SPR system (2.0 × 10 −5 RIU). To further boost intense signal enhancement, customdesigned gold nanorods (AuNRs), which were optimized by the finite-difference time-domain (FDTD) simulation, were used to generate localized surface plasmon resonance (LSPR). By exploiting the estrogen receptor as the recognition material, estrogenic active chemicals were detected with a 17β-estradiol/L detection limit of 0.004 ng, which is nearly 180-fold lower than that of the system without introducing AuNRs. The developed SPR biosensor is expected to be capable of screening various EDCs with universality by using several nuclear receptors, such as the androgen receptor and thyroid receptor, and will substantially accelerate the assessment of global EDCs.

Surface plasmonic biosensors: principles, designs and applications

“…In 2023, Tan et al used a novel optical structure to amplify the refractive index change on the surface of gold-plated SPR chips. 76 And the signal is further enhanced by the introduction of custom gold nanorods. The detection limit for estradiol, a metric, was improved nearly 180-fold over the system that did not use gold nanorods.…”

Fabrication of an Antifouling Surface Plasmon Resonance Sensor with Stratified Zwitterionic Peptides for Highly Efficient Detection of Peanut Allergens in Biscuits

“…Surface plasmon resonance sensors (SPRs), possessing the advantages of nonlabeling, high sensitivity, and high efficiency, have been widely applied in many fields, such as clinical diagnosis, environment monitoring, , and food safety, , which provides an excellent strategy for the detection of peanut allergens . However, when faced with complex food substances, the fouling problem caused by the nonspecific adsorption of food substances on the sensors is a severe challenge in real-sample detection, which has become a common failing for almost all sensors. , Food matrixes may adsorb on the sensing interface, inducing nonspecific responses, and further affect the capability of target recognition .…”

Novel flexible magnetoelastic biosensor based on PDMS/FeSiB/QD composite film for the detection of African swine fever virus P72 protein

“…In recent years, by modifying antigens on the SPR chips, Tan et al have developed a biosensor with ultra-low detection limits to detect a wide range of trace contaminants. [11][12][13][14] Antibody-modied biosensors can specically capture their corresponding antigens, which have high specicity and sensitivity when detecting target antigens. Guo et al developed an antibody-modied biosensor to achieve portable, high-sensitivity detection of the Osteoarthritis marker MMP-3.5.…”