TABLE 2.

SPRs based DNA detection techniques.

Type of Affinity Assay	Determination Method	LOD	Analyte Range DLR	References
Silica core/gold nanowires	SPR/a novel design of a highly sensitive surface plasmon photonic crystal fiber biosensor for DNA hybridization detection is presented	5.53–6.82 RIU-1	94.59 nm/RIU	Azab et al. (2018)
Au/SiO2/H2O/L inker	SPR/A highly sensitive hybrid plasmonic slot-waveguide biosensor based on silicon-on-insulator is proposed which record change in the analyte refractive index	2.65 × 10−6 RIU	1890.4 nm/RIU	Hameed et al. (2017)
Biotinylated thiolated DNA molecular beacon (MB)/streptavidin functionalized gold nanorods	SPR/strategy by applying biotinylated thiolated molecular beacon (MB) interfacial gene probe and a strepavidinylated GNR (Stre-GNR) for the enhanced SPR response to realize rapid and sensitive miRNA detection is demonstrated	0.045 pM	0–2 nM	Hao et al. (2017)
Nanobowled Aluminum/Au NPs	LSPR/fabricated ordered gold nanoparticle arrangements on epoxy substrates is presented	5 nM	1–1,000 nM	Lednický and Bonyár (2020)
Gold nanostar (AuNS)/SPR	SPRi/Designed sandwich-like assay based on the selective capturing of specific DNA targets and the subsequent signal amplification by a secondary DNA probe linked to AuNS	3.0 fM (without NSs) 6.9 aM (with NSs)	6.1 nM–10 pM (without NSs)	Mariani et al. (2015)
			1.5 fM–10 aM (with NSs)
3D gold nanostructure with Au deposition	LSPR of gold nanoparticles is sensitive to the dielectric constant of the surrounding environment	1–500 nM	13 fM	Na et al. (2018)
Au nanoparticles	LSPR peak is sensitive only to the refractive index of the close surrounding environment	430 nm/RIU	0–100 nM	Qi and Bi (2019)
Graphene/Au NPs	SPR/Sensitive polarization control-modulated plasmonic biosensor based on monolayer graphene at gold film- $\pi$ -staking interaction	500 aM	10−15 to 10−7 M	Sun et al. (2019b)
Gold nanorods	Using LSPR/establish a method that can discriminate between the mutant and the wild-type sequence of the gene using gold nanorods in solution	2 ng/mL	0–125 ng/mL	Tadimety et al. (2019)
Inverted-bowtie nanoapertures	SPR/show simultaneous ionic-current and optical-transmission-based detection of DNA	100 nm		Verschueren et al. (2019)
Dual Gold Nanoparticles	SPR/Dual nanoparticle amplification was achieved by controlled hybridization attachment of AuNPs resulting from electronic coupling between the Au film and AuNPs, as well as coupling effects in plasmonic nanostructures	5 × 103 exosomes/mL	106–109 exosomes/mL	Wang et al. (2019b)
Gold NPs	LSPR/AuNPs bind with DNA, this binding changes the local refractive index, which is detected spectroscopically as the resulting changes of the LSPR peak wavelength	60 nM	0–31 nM	Zopf et al. (2019)
Silicon dioxide Microfluidic	LSPR/developed a label-free microfluidic biosensor platform to detect the interaction of DNA with the DNA polymerase enzyme, to monitor the formation of Self-assembled-monolayers of ssDNA	54 ± 6 nm/RIU	0.0625 U/mL	Roether et al. (2019)