Rapid and Accurate On-Site Immunodiagnostics of Highly Contagious Severe Acute Respiratory Syndrome Coronavirus 2 Using Portable Surface-Enhanced Raman Scattering-Lateral Flow Assay Reader.

In early 2022, the number of people infected with the highly contagious mutant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), called Omicron, was increasing worldwide. Therefore, several countries approved the lateral flow assay (LFA) strip as a diagnostic method for confirming SARS-CoV-2 instead of reverse transcription-polymerase chain reaction (RT-PCR), which takes a long time to generate the results. However, owing to the limitation of detection sensitivity, commercial LFA strips have high false-negative diagnosis rates for patients with low virus concentrations.

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

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 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.

Development of Label-Free Colorimetric Assay for MERS-CoV Using Gold Nanoparticles.

Worldwide outbreaks of infectious diseases necessitate the development of rapid and accurate diagnostic methods. Colorimetric assays are a representative tool to simply identify the target molecules in specimens through color changes of an indicator (e.g.

Raman spectrum identification based on the correlation score using the weighted segmental hit quality index.

In this paper, we consider a novel method for identification of Raman spectra recorded on different instruments with different wavelengths. Since the conventional hit quality index (HQI) is vulnerable to intensity variation, it needs intensity calibration or standardization for each spectrometer, which causes additional time consuming work. To simplify this process and enhance the identification performance, we propose a new scoring method which is defined as the weighted sum of the HQIs from segmented spectra by windowing.

Electrochemical Fabrication of Nanostructures on Porous Silicon for Biochemical Sensing Platforms.

We present a method for the electrochemical patterning of gold nanoparticles (AuNPs) or silver nanoparticles (AgNPs) on porous silicon, and explore their applications in: (1) the quantitative analysis of hydroxylamine as a chemical sensing electrode and (2) as a highly sensitive surface-enhanced Raman spectroscopy (SERS) substrate for Rhodamine 6G. For hydroxylamine detection, AuNPs-porous silicon can enhance the electrochemical oxidation of hydroxylamine. The current changed linearly for concentrations ranging from 100 μM to 1.

Application of a SERS-based lateral flow immunoassay strip for the rapid and sensitive detection of staphylococcal enterotoxin B.

A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity).

Large-scale plasma patterning of transparent graphene electrode on flexible substrates.

Graphene, a two-dimensional carbon material, has attracted significant interest for applications in flexible electronics as an alternative transparent electrode to indium tin oxide. However, it still remains a challenge to develop a simple, reproducible, and controllable fabrication technique for producing homogeneous large-scale graphene films and creating uniform patterns with desired shapes at defined positions. Here, we present a simple route to scalable fabrication of flexible transparent graphene electrodes using an oxygen plasma etching technique in a capacitively coupled plasma (CCP) system.

Ultrasensitive trace analysis for 2,4,6-trinitrotoluene using nano-dumbbell surface-enhanced Raman scattering hot spots.

We report an ultra-sensitive surface-enhanced Raman scattering (SERS)-based detection system for 2,4,6-trinitrotoluene (TNT) using nano-dumbbell structures formed by the electrostatic interaction between positively and negatively charged gold nanoparticles. First, Meisenheimer complexes were produced between TNT and l-cysteine on gold substrates, and 4-mercaptopyridine (4-MPY) labeled gold nanoparticles (positively charged) were allowed to interact with the Meisenheimer complexes through the electrostatic interaction between the negatively charged aromatic ring of the complex molecules and the positively charged nanoparticles. Then, negatively charged gold nanoparticles were added in order to form nano-dumbbells.