Quantitative Serodiagnosis of Scrub Typhus Using Surface-Enhanced Raman Scattering-Based Lateral Flow Assay Platforms

Abstract

A surface-enhanced Raman scattering-based lateral flow assay (SERS-LFA) technique has been developed for the rapid and accurate diagnosis of scrub typhus. Lateral flow kits for the detection of O. tsutsugamushi IgG (scrub typhus biomarker) were fabricated, and the calibration curve for various standard clinical sera concentrations were obtained by Raman measurements. The clinical sera titer values were determined by fitting the Raman data to the calibration curve. To assess the clinical feasibility of the proposed method, SERS-LFA assays were performed on 40 clinical samples. The results showed good agreement with those of the standard indirect immunofluorescence assay (IFA) method. SERS-LFA has many advantages over IFA including the less sample volume, simpler assay steps, shorter assay time, more systematic quantitative analysis, and longer assay lifetime. As SERS strips can be easily integrated with a miniaturized Raman spectrophotometer, field serodiagnosis is also more feasible.

Diagnosis of scrub typhus: recent advancements and challenges

“…It has been demonstrated that the sensitivity of ICT increased by 20% when used in combination with DNA-based loop-mediated isothermal PCR assay (Blacksell et al 2012 ). To achieve the higher sensitivity and accuracy in the diagnosis of scrub typhus, a surface-enhanced Raman scattering-based lateral flow assay (SERS-LFA) has been developed (Lee et al 2019 ). The developed assay can perform the quantitative analysis of samples, which is not possible with the normal lateral flow assay.…”

“… ELISA IgM 95.5 88.0 Saraswati et al ( 2019 ) 2. SERS-LFA 56 kDa tissue specific antigen 100 100 Lee et al ( 2019 ) 3. Real-time PCR HtrA 70.5 69.7 Rawat et al ( 2018 ) ELISA IgM IgG 82.7 75 96.4 91 4.…”

“…New studies suggested using these immuno-based approaches to develop the integrated sensors to improve the sensitivity and specificity of the sensor. An effort has been made to develop a lateral flow assay (LFA) based sensor, which integrates the LFA strips with the miniaturized Raman spectrophotometer to make it a quantitative method feasible for field testing (Lee et al 2019 ). So such integrated biosensors can be developed to overcome the limitations of present immuno-based approaches, which is facing the problem of poor stability and higher cost.…”

Development of a SERS-based lateral flow immunoassay for rapid and ultra-sensitive detection of anti-SARS-CoV-2 IgM/IgG in clinical samples

“…In this study, we proposed a real-time two-channel surface-enhanced Raman scattering (SERS)-based LFIA biosensor to simultaneously detect anti-SARS-CoV-2 IgM/IgG with high sensitivity. SERS-LFIA strip is a new promising analytical technology that integrates functional SERS-encoded nanoparticles (NPs), also called SERS nanotags, into the LFIA system instead of the commonly used Au NPs as the signal reporter [ [18] , [19] , [20] ]. This technology can offer strong (high-sensitivity), specific (fingerprint feature), and stable (no photobleaching) SERS signals.…”

Rapid, Quantitative, High-Sensitive Detection of Escherichia coli O157:H7 by Gold-Shell Silica-Core Nanospheres-Based Surface-Enhanced Raman Scattering Lateral Flow Immunoassay

“…However, the inherent defects of conventional LFIA are poor quantitative ability and limited detection sensitivity, which both depend on colorimetric analysis. Increasing attention has been paid to surface-enhanced Raman Scattering (SERS)-based LFIA technology, which combines the high sensitivity and quantitative analysis of SERS technology and the rapidity and convenience of LIFA (Hwang et al, 2016;Lee et al, 2019;Wang et al, 2019b). SERS-based LFIA uses Raman reporter-labeled SERS nanomaterials instead of colloidal Au as the signal tags, thereby providing strong and stable SERS signals (Jia et al, 2018;Khlebtsov et al, 2018).…”