The COVID-19 pandemic is a once-in-a-lifetime public health threat. The pandemic has had a significant impact on both individuals and communities’ health, safety, and well-being. Because COVID-19 is an extremely infectious and has nonspecific symptoms that are easily confused with the typical flu, it is critical to have precise diagnostic techniques readily available. There is an urgent need for quick detection of the SARS-CoV-2 virus due to the COVID-19 pandemic. Here, we present highly sensitive gold nanoparticle-enhanced localized surface plasmon resonance (LSPR) technique for detection of SARS-CoV-2 virus. Surface plasmon resonance is a powerful method for getting label-free, real-time information about the interaction of two binding partners. Gold nanoparticles (AuNPs) were used as signal enhancers in the diagnosis of SARS-CoV- 2 virus using the LSPR technique. Gold nanoparticles are stable against oxidation, great biocompatible, non-cytotoxic and have unique optical characteristics. These specific properties make AuNPs the most potential nanomaterial for different applications such as ultrasensitive detection and biological sensing.
Chitosan-based nanoparticles (NPs) are well-known for their safely, nontoxicity, biocompatibility, and biodegradability. Since highly infectious viral diseases such as Covid-19 spread quickly, it is important to be able to diagnose these diseases early to prevent the infection from spreading. In this study, we developed a novel highly sensitive chitosan/gold nanoparticles based LSPR sensor for SARS-CoV-2 virus detection. Localized surface plasmon resonance (LSPR) is an optical phenomenon caused by collective electron charge oscillations in metallic nanoparticles excited by light source. The nanocomposites of gold nanoparticles (AuNPs) with chitosan were synthesized by the reduction technique. Chitosan/Au nanocomposites were synthesized by reducing gold salt using chitosan. Chitosan acted as a reducing/stabilizing agent to produce composites. SARS-CoV- 2 antibodies were conjugated with Chitosan/Au nanocomposites for detection of the target antigen using LSPR.
In genetic research, detecting mutations in the genome is very important. In cancer research, identifying mutations that are responsible for the development of the disease is vital for managing the progression and spread of the disease. Identifying subtle mutations in sequences is difficult, and more sensitive methods are required. To this end, different techniques have been developed to detect these mutations. The increasing number of techniques suggests that a perfect technique is yet to be identified. Localized surface plasmon resonance (LSPR) biosensor is an efficient alternative technique for detecting mutations due to its highly confined and enhanced electric fields near an interface with rapid evanescent decay. LSPR does not need to be equipped with additional optical coupling devices, such as prisms or angular detectors. Further, its strong scattering coefficients and absorption capabilities eliminate the need for polarization restrictions. The low field decay length of 10-30 nm and the low sensitivity to bulk RI changes and stability to temperature fluctuations allow it to accurately track analytes close to their surfaces, and consequently detect small biological interactions. In this study, LSPR was able to detect and differentiate interactions between 100% complementary DNA sequences and uncomplimentary DNA sequences. Oligonucleotide probes immobilized on a gold-coated sensor slide were used as a source of DNA sequence, and the acquired results indicated that LSPR was successfully able to recognize changes between samples of 100% DNA hybridization and those with uncomplimentary sequences. Based on these results, LSPR can be used as a potential technique in the detection of viral mutation at a faster rate.
Plasmonic biosensing is an area of research where scientists are developing novel devices and concepts. The validation of these devices requires thorough testing of key characteristics, including accuracy, specificity, robustness, and linearity, all of which are interconnected with a system's limit of detection. By optimizing parameters to meet these criteria, the development of highly sensitive and specific biosensing devices can be facilitated, allowing for effective performance comparisons with other biosensing devices. The limit of detection is a measure of the ability to detect small traces of molecules in each solution, and it can be used to measure the performance of a biosensing system. In this study, we evaluated the limit of detection of a home-built localized surface plasmon resonance (LSPR) system. To this end, gold-coated and titanium-coated slides were exposed to neutravidin and biotinylated probes at varying concentrations ranging from 100 μM to 6.125 μM, without the presence of an analyte. By analyzing the transmitted intensity against concentration, we constructed a reliable sensing curve. Through linear regression analysis, we determined the slope of the linear calibration function with high precision. By evaluating the limit of detection, this study will contribute to the understanding of the performance capabilities of the localized surface plasmon resonance technique. The findings presented here serve as a valuable benchmark for developing and comparing highly sensitive and specific biosensing devices.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.