Fig. 1. Methods for virus detection based on SPR or LSPR technique

Fig. 2. Virus detection using AuNRs. (a) Detection principle of AuNRs nanosensor^[41]; (b) scanning electron microscopy (SEM) image of filter paper with AuNR-ZIKV-NS1 conjugate^[42]; (c) extinction spectra at different regions of BPD^[42]; (d) activity changes of ZIKV-NS1 on BPD under different storage conditions^[42]

Fig. 3. Working diagrams of LSPR biosensor chip^[59]. (a) Schematic of virus detection by heteroassembled AuNPs chip; (b) schematic of sandwich structure composed of AuNPs and heteroassembled AuNPs layer for virus detection

Fig. 4. Schematic of multi-functional DNA 3-way connected HAuSN sensor^[62]

Fig. 5. Nanostructure of EBOV sensor and fluorescence sensing method^[64]. (a) Structural diagram of 3D nano-antenna LSPR sensor chip; (b) decomposition diagram of sandwich structure

Fig. 6. Schematic of immune-fluorescence biosensor magnified by LSPR^[65]

Fig. 7. Enzymatic or non-enzymatic amplification using DNA technique

Fig. 8. AuNPs modification of W(Mo)S₂ film rich in GB and its SEM diagram^[84]

Fig. 9. LSPR combined with QDs to enhance sensitivity. (a) Mechanism diagams of DENV detection using AuNPs and hairpin ssDNA-CdSeTeS QDs^[85]; (b) schematics of four NP-Qdot-MB biosensor probes for ZIKV detection^[86]

Fig. 10. Sensors with sandwich structure. (a) Plasma sensor with gold layer-virus-gold nanorod sandwich structure^[97]; (b) plasma sensor with gold cup array-virus-gold nanoparticle sandwich structure^[98]

Fig. 11. AuNP-QD sensing probe. (a) Schematic of fluorescence intensity of adjacent QDs enhanced by LSPR effect of AuNPs^[106]; (b) mechanism of virus detection using CdSeTeS QDs/AuNPs rigid sensing probe^[107]; (c) mechanism of virus detection with adjustable length of intermediate junction peptide^[108]; (d) fluorescence quenching of QDs after virus captured by CdZnSeS/ZnSeS QD-peptide-AuNP sensor^[108]

Fig. 12. Fluorescence spectral bar diagrams of CdSe QDs in various CdSe QD-peptide-AuNP nano-conjugates^[109]. AuNPs with six different sizes of (a) 80 nm, (b) 60 nm, (c) 45 nm, (d) 35 nm, (e) 25 nm, and (f) 15 nm combined with peptide with six different lengths to produce different fluorescence intensity changes; (g) effect of AuNPs with concentrations of 10¹², 10⁹, and 10⁶ mL^－1 on nano-conjugates with other constant parameters

Fig. 13. Sensor antifouling and reuse scheme. (a) Schematic of protein modified by polymer brush^[111]; (b) trapping of magnetic particles on reusable SPR chip through external magnetic field^[112]; (c) removal of magnetic particles by external magnetic field opposite to trapping direction^[112]