Gold nanoparticle-streptavidin conjugates for rapid and efficient screening of aptamer function in lateral flow sensors using novel CD4-binding aptamers identified through Crossover-SELEX

Ho, Lance St John; Flanagan, Shane; Fogel, Ronen; Ojo, Dupe; Limson, Janice

doi:10.1039/d0an00634c

Cited by 20 publications

(10 citation statements)

References 72 publications

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“…Here, we present an aptamer-based POC lateral flow assay , that measures cortisol concentration in saliva by providing a colorimetric signal in the test strip. We have previously reported the aptamer-based detection of cortisol in sweat using the mechanism of salt aggregation.…”

Section: Introductionmentioning

confidence: 99%

Aptamer-Based Lateral Flow Biosensor for Rapid Detection of Salivary Cortisol

2020

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We have developed a disposable point-of-care (POC) aptamer-based biosensor for the detection of salivary cortisol. Nonstressful and noninvasive sampling of saliva compared to that of blood makes saliva an attractive biological matrix in developing POC devices for biomarker monitoring. Aptamers are attractive as recognition elements for multiple reasons, including their specific chemical synthesis, high stability, lack of immunogenicity, and cell-free evolution. A duplex aptamer conjugated to the surface of Au nanoparticles (AuNPs) by Au–S bonds is utilized as the sensor probe in a lateral flow assay (LFA) device. The addition of saliva samples containing cortisol makes the cortisol–aptamer undergo conformational changes and dissociate from the capture probe. Increasing cortisol concentration in the dispensed saliva sample results in increased dissociation and leads to increased binding of AuNP conjugate on the test line. Therefore, the color intensity of the test line on the LFA is a direct function of the concentration of cortisol in saliva. This simple and fast method provides detection in the cortisol range of ∼0.5–15 ng/mL, which is in the clinically accepted range for salivary cortisol. The limit of detection was 0.37 ng/mL, and the accuracy was confirmed by enzyme-linked immunosorbent assay (ELISA) testing results. High selectivity was observed for salivary cortisol against other closely related steroids and stress biomarkers present in saliva.

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Section: Introductionmentioning

confidence: 99%

Aptamer-Based Lateral Flow Biosensor for Rapid Detection of Salivary Cortisol

2020

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“…The sample pad fabricated from glass fibers was thoroughly wetted with a buffer of pH 8.0 (2% glucose, 1% Triton, 50 mM boric acid, 1% BSA), dried, and then kept in a desiccant container. The conjugate pad, also made of glass fibers, was embedded with the AuNP-SA solution [ 32 ] and dried thoroughly before use. Using a dispenser machine, the test and control lines on the NC membrane were sprayed with a customized DNA capture probe and biotinylated rabbit polyclonal anti-IgG antibody solutions, respectively.…”

Section: Methodsmentioning

confidence: 99%

Rational Programming of Cas12a for Early-Stage Detection of COVID-19 by Lateral Flow Assay and Portable Real-Time Fluorescence Readout Facilities

Habimana

Mukama

et al. 2021

Biosensors

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Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus has led to a global pandemic with a high spread rate and pathogenicity. Thus, with limited testing solutions, it is imperative to develop early-stage diagnostics for rapid and accurate detection of SARS-CoV-2 to contain the rapid transmission of the ongoing COVID-19 pandemic. In this regard, there remains little knowledge about the integration of the CRISPR collateral cleavage mechanism in the lateral flow assay and fluorophotometer. In the current study, we demonstrate a CRISPR/Cas12a-based collateral cleavage method for COVID-19 diagnosis using the Cas12a/crRNA complex for target recognition, reverse transcription loop-mediated isothermal amplification (RT-LAMP) for sensitivity enhancement, and a novel DNA capture probe-based lateral flow strip (LFS) or real-time fluorescence detector as the parallel system readout facility, termed CRICOLAP. Our novel approach uses a customized reporter that hybridizes an optimized complementary capture probe fixed at the test line for naked-eye result readout. The CRICOLAP system achieved ultra-sensitivity of 1 copy/µL in ~32 min by portable real-time fluorescence detection and ~60 min by LFS. Furthermore, CRICOLAP validation using 60 clinical nasopharyngeal samples previously verified with a commercial RT-PCR kit showed 97.5% and 100% sensitivity for S and N genes, respectively, and 100% specificity for both genes of SARS-CoV-2. CRICOLAP advances the CRISPR/Cas12a collateral cleavage result readout in the lateral flow assay and fluorophotometer, and it can be an alternative method for the decentralized field-deployable diagnosis of COVID-19 in remote and limited-resource locations.

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“…Besides, some groups have developed SELEX strategies based on other microdevices, such as electrochemical electrode, , paper-based lateral flow sensor, , particle-encoded platform, etc. Zourob et al designed an electrochemical platform for SELEX based on the immobilization of the target small molecules on gold electrodes (Figure B).…”

Section: Aptamer Selection By Microdevicesmentioning

confidence: 99%

“…The high-affinity aptamers for 11-deoxycortisol hormone were successfully selected after eight rounds and can be possibly applied in serum samples. On the other hand, nitrocellulose strip-based lateral flow assay (LFA) for the screening of CD4-specific DNA aptamers was reported . The screening process termed as crossover-SELEX utilizes streptavidin-conjugated gold nanoparticles as reporter molecules.…”

Section: Aptamer Selection By Microdevicesmentioning

confidence: 99%

Aptamer-Functionalized Microdevices for Bioanalysis

Xue

Chen

Bai

et al. 2020

ACS Appl. Mater. Interfaces

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Aptamers have drawn great attention in the field of biological research and disease diagnosis for the remarkable advantages as recognition elements. They show unique superiority for facile selection, desirable thermal stability, flexible engineering, and low immunogenicity, complementing the use of conventional antibodies. Aptamer-functionalized microdevices offer promising properties for bioanalysis applications because of the compact sizes, minimal reaction volume, high throughput, operational feasibility, and controlled preciseness. In this review, we first introduce the innovative technologies in the selection of aptamers with microdevices and then highlight some advanced applications of aptamer-functionalized microdevices in bioanalysis field for diverse targets. Aptamerfunctionalized microfluidic devices, microarrays, and paper-based and other interface-based microdevices are all bioanalysis platforms with huge potential in the near future. Finally, the major challenges of these microdevices applied in bioanalysis are discussed and future perspectives are also envisioned.

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Gold nanoparticle-streptavidin conjugates for rapid and efficient screening of aptamer function in lateral flow sensors using novel CD4-binding aptamers identified through Crossover-SELEX

Abstract: Adaptation of conventional lateral flow tests: demonstration of a lateral flow assay in which gold nanoparticle conjugates, when bound to aptamers, serve as a reporting system to screen novel aptamers for the ability to bind to target proteins.

Cited by 20 publications

References 72 publications

Aptamer-Based Lateral Flow Biosensor for Rapid Detection of Salivary Cortisol

Aptamer-Based Lateral Flow Biosensor for Rapid Detection of Salivary Cortisol

Rational Programming of Cas12a for Early-Stage Detection of COVID-19 by Lateral Flow Assay and Portable Real-Time Fluorescence Readout Facilities

Aptamer-Functionalized Microdevices for Bioanalysis

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