## 4 SERS-Based Diagnostic Devices and Assay Platforms
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Disease** & **Target** & **Detection Scheme** & **Transducer** & **LOD** & **Ref.** \\ \hline \multicolumn{5}{c}{**Mosquito-borne Infectious Diseases**} \\ \hline West Nile Virus & Viral DNA & Indirect SERS & Parameterispatories and gold & 20-100 nM & [92] \\  & & & & nanoparticles & \\ \hline Dengue & Viral DNA & Indirect SERS & Gold and silver Nanowaves & 6 attomodes & [94] \\ \hline Malaria & Parasitic DNA & Indirect SERS & nanoparticles and magnetic beads & 3 picomed & [95] \\ \hline Malaria & Ribosomal RNA in infected blood lysates & Indirect SERS & Nanoparticles and magnetic beads & 200 nM & [96] \\ \hline Zika & 2 RXV Nonstructural protein [1 \(\overline{\text{NS}}\)] protein & Indirect SERS & Silica-coated gold nanoparticles & 10 mg/mL & [97] \\ \hline West Nile Virus & WNN’s protein & Indirect SERS & Gold Nanostars & 2 mg/mL & [98] \\ \hline West Nile Virus & WNN’s protein & Indirect SERS & Gold nanoparticles and Paramagnetic & 5 g/mL & [99] \\ \hline West Nile Virus & Valley Fever Virus and & Viral pathogenic antigens & Indirect SERS & Silica-coated gold nanoparticles and & 10 pg/mL & [100] \\ Versnintis & & & Paramagnetic nanoparticles & & \\ \hline Hard, Foot and Mouth Disease causing virus & Enterovirus 71 (EVT1) & Direct SERS & Gold Nanostars & 100 n/ 10^9 pft/mL & [101] \\ \hline Zika and Dengue & Nonstructural protein 1 (SSI) & Indirect SERS & Gold Nanostars & 0.72 mg/mL of 2 RXV N51 and 7.87 & [102] \\ \hline West Nile Virus and Dengue & DENV2 and WNN’s proteins in serum & Direct SERS & Gold nanoparticles & 10 pft/mL & [103] \\ Malaria & Plasmodium falciparum viral red blood cells & Direct SERS & Silver nanorod & \(1.5\times 10^{7}\)/mL & [104] \\ \hline Malaria & Hemonon in iRBC & direct SERS & Iron oxide core and silver shell & 5 nM & [113] \\ \hline Malaria & Hemonon in iRBC & direct SERS & Silver nanoparticles & 2.5 parasites/ml & [105] \\ \hline Malaria & Hemonon in iRBC lysate & direct SERS & Gold-coated butterfly wings & 0.0005\% and 0.005\% & [114] \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._Among many different approaches, microfluidic devices, lateral-flow assays, and lab-on-a-chip assays are the most common diagnostic assay platforms that have been developed and tested for infectious diseases [94; 115; 116; 117; 118; 119; 120]. SERS-based assays have been integrated into these devices to be used for both qualitative and quantitative biomarker detection [7; 8; 70; 73; 91; 94; 121; 122; 123; 124]. Integration of SERS detection schemes into lateral flow assays are commonly seen in the recent work related to infectious disease diagnosis [91; 122]. Paper-based immunoassay such as LFA are desirable at the POC as they are cost-efficient and can be user friendly for a non- technically specialized end user. For instance, [PERSON], et al. developed a simplified LFA using hollow gold nanoparticles encoded with Raman tags and functionalized with antibodies as the SERS detection probe to specifically capture and detect staphylococcal enterotoxin B (SEB), which is a common food-poisoning pathogen (Figure 8) [122]. This approach was able to yield highly sensitive quantitative detection of SEB based on the SERS signals measured at the test zone, where the SEB-antibody conjugated SERS probe complex exist. The reported LOD for SEB using this SERS-based LFA strip was estimated to be 0.001 ng mL\({}^{-1}\), which is in the range required for SEB to cause intoxication (less than 1 ng mL\({}^{-1}\)). In comparison to the enzyme-linked immunosorbent assay (ELISA)-based method, the SERS-based LFA provides approximately three orders of magnitude higher detection sensitivity. [PERSON]'s group also developed LFAs using SERS nanotags for dengue and Zika detection [70; 125]. The importance of their study is that they systematically examined the importance of gold nanostar morphological features and Raman reporter selection in order optimize the SERS enhancement and multiplexed detection in LFAs, respectively.