Exploiting the Anti-Aggregation of Gold Nanostars for Rapid Detection of Hand, Foot, and Mouth Disease Causing Enterovirus 71 Using Surface-Enhanced Raman Spectroscopy

Abstract

Enterovirus 71 (EV71) is a major public health threat that requires rapid point-of-care detection. Here, we developed a surface-enhanced Raman spectroscopy (SERS)-based scheme that utilized protein-induced aggregation of colloidal gold nanostars (AuNS) to rapidly detect EV71 without the need for fabricating a solid substrate, Raman labels or complicated sample handling. We used AuNS (hydrodynamic diameter, D of 105.12 ± 1.13 nm) conjugated to recombinant scavenger receptor class B, member 2 (SCARB2) protein with known affinity to EV71. In the absence of EV71, AuNS-SCARB2 aggregated in biological media and produced four enhanced Raman peaks at 390, 510, 670, and 910 cm. In the presence of EV71, the three peaks at 510, 670, and 910 cm disappeared, while the peak at 390 cm diminished in intensity as the virus bound to AuNS-SCARB2 and prevented them from aggregation. These three peaks (510, 670, and 910 cm) were potential markers for specific detection of EV71 as their disappearance was not observable with a different dengue virus (DENV) as our control. Furthermore, the Raman measurements from colloidal SERS were more sensitive in probing the aggregation of AuNS-SCARB2 for detecting the presence of EV71 in protein-rich samples compared to UV-vis spectrum measurements. With this facile "anti-aggregation" approach, we were able to detect EV71 in protein-rich biological medium within 15 min with reasonable sensitivity of 10 pfu/mL and minimal sample preparation, making this translatable for point-of-care applications.

A rapid and label-free platform for virus capture and identification from clinical samples

“…Interestingly, this Raman signal enhancement enables the detection down to a single-molecule level (approximately picomolar) (35,36). Previous studies have demonstrated that SERS can collect fingerprints of pure viruses prepared by ultracentrifugation or by conjugating antibodies on a metal surface to isolate or capture viruses (37)(38)(39). We observed that Au nanoparticles of ∼15 nm in diameter are well distributed on CNxCNT (SI Appendix, Figs.…”

Recent Advancement in the Surface-Enhanced Raman Spectroscopy-Based Biosensors for Infectious Disease Diagnosis

“…Protein-induced plasmonic nanoparticle aggregation has also been used to detect protein biomarkers using their intrinsic SERS signatures (direct SERS). Kah et al used gold nanostars (GNS) to design an approach for label-fee direct SERS detection of Enterovirus 71 (EV71) [101]. This approach is very attractive for POC diagnosis given the fact that it is based on the intrinsic SERS of proteins ( Figure 5).…”

Anisotropic Gold Nanoparticles in Biomedical Applications

“…The high impact that gold-based nanomaterials could have on daily human health can be verified by the studies developed to detect viruses or antibiotic resistance bacteria. Recently, AuNUs have been developed with the final goal to early detect the presence of human enterovirus, the EV71, in biological media [ 82 ]. This enterovirus can provoke the quite diffuse hand, foot and mouth disease and it is associated with neurologic and systemic complications.…”