Magnetic-Responsive Surface-Enhanced Raman Scattering Platform with Tunable Hot Spot for Ultrasensitive Virus Nucleic Acid Detection

Abstract

Surface-enhanced Raman scattering (SERS)-based biosensors are promising tools for virus nucleic acid detection. However, it remains challenging for SERS-based biosensors using a sandwiching strategy to detect long-chain nucleic acids such as nucleocapsid (N) gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) because the extension of the coupling distance (CD) between the two tethered metallic nanostructures weakens electric field and SERS signals. Herein, we report a magnetic-responsive substrate consisting of heteoronanostructures that controls the CD for ultrasensitive and highly selective detection of the N gene of SARS-CoV-2. Significantly, our findings show that this platform reversibly shortens the CD and enhances SERS signals with a 10-fold increase in the detection limit from 1 fM to 100 aM, compared to those without magnetic modulation. The optical simulation that emulates the CD shortening process confirms the CD-dependent electric field strength and further supports the experimental results. Our study provides new insights into designing a stimuli-responsive SERS-based platform with tunable hot spots for long-chain nucleic acid detection.

Temperature-Responsive Nanocarrier-Regulated Alternative Release of “Cargos” for a Multiplex Photoelectrochemical Bioassay of Antibiotic-Resistant Genes

“…Pioneering studies on stimuli-responsive materials, in response to various external stimuli (e.g., pH, temperature, humidity, redox or UV light, etc.) have recently received substantial attention, including in drug delivery, biomedical uses and biosensing. − Especially, the intriguing concept of stimulus-responsive gatekeeping was introduced as a means of regulating the release of cargo molecules. Upon stimulation, the “gatekeeper”, that is, the capping agents in the gated system could be maneuvered to release “cargo” from the reservoir into a specific environment.…”

Nanomaterials for virus sensing and tracking

“…79,83 These MNPs can act as transducers, catalysts as well as complexing agents for magnetic enrichment. [292][293][294][295][296][297][298] Since interferents and non-specific molecules in complex biological media are nonmagnetic in nature, virus detection with magnetic sensors is significantly more sensitive than optical and electrochemical techniques. 299 Therefore, several promising techniques such as giant magnetoresistance (GMR), 300,301 magnetic particle spectroscopy (MPS), 302,303 magnetic inductance, 260 and magnetic tunneling junction 304,305 are being explored for virus recognition.…”

AKR1B10, One of the Triggers of Cytokine Storm in SARS-CoV2 Severe Acute Respiratory Syndrome

“…Nonetheless, the 2 of 14 vaccination appears insufficient to completely prevent the circulation of the virus, and the occurrence of severe forms requiring the Intensive Care Unit (ICU) is still associated with high mortality rates [3]. Hence, developing new approaches to detect SARS-CoV2 infection [4,5] and preventing the occurrence of the most severe cases of Acute Respiratory Distress Syndrome (ARDS) associated with severe COVID-19 forms represents a crucial strategy to reduce the burden of the COVID-19 pandemic. Although COVID-19 is associated with a wide range of symptoms [6], life-threatening ARDS are tightly triggered by a massive inflammatory burst, named a cytokine storm [7].…”