An Ultrasensitive and Universal Surface Plasmonic Biosensor for Detection of Micropollutants in Aquatic Environments

Abstract

Simple yet ultrasensitive and accurate quantification of a variety of analytical targets by virtue of a universal sensing device holds promise to revolutionize environmental monitoring, medical diagnostics, and food safety. Here, we propose a novel optical surface plasmon resonance (SPR) system in which the frequency-shifted light of different polarizations returned 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. In addition, the s-polarized light was further used as the reference to compensate the noise of the LHFI-amplified SPR system, resulting in nearly 3 orders of magnitude enhancement of RI resolution (5.9 × 10–8 RIU) over the original SPR system (2.0 × 10–5 RIU). By exploiting nucleic acids, antibodies, and receptors as recognition materials, a variety of micropollutants were detected with ultralow detection limits, ranging from a toxic metal ion (Hg2+, 70 ng/L) to a group of commonly occurring biotoxin (microcystins, 3.9 ng microcystin-LR/L) and a class of environmental endocrine disruptors (estrogens, 0.7 ng 17β-estradiol/L). This sensing platform exhibits several distinct characteristics, including dual improvement of sensitivity and stability and common-path optical construction without needing optical alignment, demonstrating a promising avenue toward environmental monitoring.

Iontronic Photoelectrochemical Biorecognition Probing

“…The practical applicability was confirmed by cellular experiments using nonmetastatic cancer MCF-7 and metastatic cancer MDA-MB-231 cells and the real sample experiments using human serum. This work features a new iontronic PEC mechanism for biological probing, which is expected to catalyze a family of new PEC nanotools for diverse biological applications, e.g., environmental monitoring of antibiotics or pollutants …”

Effect-Targeted Mapping of Potential Estrogenic Agonists and Antagonists in Wastewater via a Conformation-Specific Reporter-Mediated Biosensor

“…To avoid interference from the matrix effect in wastewater, the samples were enriched using solid-phase extraction (SPE). SPE followed our previous work with slight modifications. , Briefly, a 500 mL water sample was extracted using an Oasis HLB column (6 cm 3 , 200 mg, Waters, USA). Afterward, the HLB columns were rinsed with 10 mL of DI water, dried under nitrogen, and eluted with 10 mL methanol.…”

Surface plasmonic biosensors: principles, designs and applications

“…In 2023, Tan et al proposed a universal SPR sensor capable of detecting environmental contaminants in water, using nucleic acids, antibodies and receptors as specific recognition molecules. 73 Common toxic metal ions, biotoxins, and endocrine disruptors in the environment are monitored (Fig. 4c).…”