Ultraviolet-induced in situ gold nanoparticles for point-of-care testing of infectious diseases in loop-mediated isothermal amplification

Lab on a Chip ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 700-709
Author(s):  
Rajamanickam Sivakumar ◽  
Vu Phong Dinh ◽  
Nae Yoon Lee
Keyword(s):  
Gold Nanoparticles ◽  
Infectious Diseases ◽  
Enterococcus Faecium ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification

The present study investigated ultraviolet-induced in situ gold nanoparticles (AuNPs) coupled with LAMP for the point-of-care testing (POCT) of two major infectious pathogens, namely, Coronavirus (COVID-19) and Enterococcus faecium (E. faecium spp.).

scholarly journals Application of Loop-Mediated Isothermal Amplification combined with colorimetric and lateral flow dipstick visualization as the potential point-of-care testing for diphtheria

2019 ◽  
Author(s):  
Aleksandra Anna Zasada ◽  
Aldona Wiatrzyk ◽  
Urszula Czajka ◽  
Klaudia Brodzik ◽  
Kamila Formińska ◽  
...  
Keyword(s):  
Detection Limit ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Lamp Assay ◽  
Corynebacterium Diphtheriae ◽  
Lateral Flow ◽  
Isothermal Amplification ◽  
Suspected Case ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification

Abstract Background Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains.Methods Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria.Results The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 minutes of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks.Conclusion The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.

scholarly journals Application of Loop-Mediated Isothermal Amplification combined with colorimetric and lateral flow dipstick visualization as the potential point-of-care testing for Corynebacterium diphtheriae

2020 ◽  
Author(s):  
Aleksandra Anna Zasada ◽  
Aldona Wiatrzyk ◽  
Urszula Czajka ◽  
Klaudia Brodzik ◽  
Kamila Formińska ◽  
...  
Keyword(s):  
Detection Limit ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Lamp Assay ◽  
Corynebacterium Diphtheriae ◽  
Lateral Flow ◽  
Isothermal Amplification ◽  
Suspected Case ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification

Abstract Background Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts.The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains.Methods Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria.Results The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 minutes of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks.Conclusion The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.

scholarly journals Rapid Electronic Diagnostics of Ebola Virus with Synthetic Nanobody-Conjugated Gold Nanoparticles

2021 ◽  
Author(s):  
Xiahui Chen ◽  
Shoukai Kang ◽  
MD Ashif Ikbal ◽  
Zhi Zhao ◽  
Jiawei Zuo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Infectious Diseases ◽  
Ebola Virus ◽  
Semiconductor Device ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Emerging Infectious Diseases ◽  
Rapid Diagnostics ◽  
Point Of Care Testing ◽  
Training Requirement

The success of controlling emerging infectious diseases relies on the fast development of robust, quantitative assays for point-of-care testing. Here a generalizable strategy is demonstrated for developing inexpensive, simple-to-use, and rapid diagnostics within a few weeks upon the identification of a new viral antigen. Using Ebola virus secreted glycoprotein (sGP) as a target, we design a new assay featuring nanobody-conjugated nanoparticles for rapid, electronic detection (Nano2RED). Nanobodies with the high affinity and specificity were generated by phage display screening of a high-quality combinatorial library (> 109) and site-specifically conjugated to gold nanoparticles (AuNPs) for in-solution colorimetric detection. Our assay can robustly detect the sGP protein from 10 pM to 100 nM in diluted serum and distinguish it from a membrane-anchored isoform, GP1,2, allowing the diagnosis of the viral infection stage. Additionally, a rapid assay protocol was established to decrease the assay time to a few minutes without compromising the accuracy. Lastly, this assay has been integrated with a portable semiconductor device with a digital readout and minimal training requirement for end users. Our method can be widely applied to the point-of-care testing of other infectious diseases.

scholarly journals Rapid, reliable, and cheap point-of-care bulk testing for SARS-CoV-2 by combining hybridization capture with improved colorimetric LAMP (Cap-iLAMP)

2021 ◽  
Author(s):  
Lukas Bokelmann ◽  
Olaf Nickel ◽  
Tomislav Maricic ◽  
Svante Pääbo ◽  
Matthias Meyer ◽  
...  
Keyword(s):  
Point Of Care ◽  
Rna Extraction ◽  
Lamp Assay ◽  
False Positives ◽  
Isothermal Amplification ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification ◽  
Hybridization Capture ◽  
Direct Addition ◽  
Single Positive

Abstract Here we present a step-by-step protocol for Cap-iLAMP (capture and improved ‎loop-mediated isothermal amplification) which combines a hybridization capture-based RNA extraction of gargle lavage samples with an improved colorimetric RT-LAMP assay and smartphone-based color scoring. Cap-iLAMP is compatible with point-of-care testing and enables the detection of SARS-CoV-2 positive samples in less than one hour. The sensitivity is 97% and the specificity is 99%. In contrast to direct addition of the sample to improved LAMP (iLAMP), Cap-iLAMP prevents false positives and allows single positive samples to be detected in pools of 25 negative samples.

scholarly journals Application of Loop-Mediated Isothermal Amplification combined with colorimetric and lateral flow dipstick visualization as the potential point-of-care testing for Corynebacterium diphtheriae

2020 ◽  
Author(s):  
Aleksandra Anna Zasada ◽  
Aldona Wiatrzyk ◽  
Urszula Czajka ◽  
Klaudia Brodzik ◽  
Kamila Formińska ◽  
...  
Keyword(s):  
Detection Limit ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Lamp Assay ◽  
Corynebacterium Diphtheriae ◽  
Lateral Flow ◽  
Isothermal Amplification ◽  
Suspected Case ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification

Abstract Background Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains. Methods Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria. Results The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 minutes of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks. Conclusion The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.

scholarly journals Application of Loop-Mediated Isothermal Amplification combined with colorimetric and lateral flow dipstick visualization as the potential point-of-care testing for Corynebacterium diphtheriae

2020 ◽  
Author(s):  
Aleksandra Anna Zasada ◽  
Aldona Wiatrzyk ◽  
Urszula Czajka ◽  
Klaudia Brodzik ◽  
Kamila Formińska ◽  
...  
Keyword(s):  
Detection Limit ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Lamp Assay ◽  
Corynebacterium Diphtheriae ◽  
Lateral Flow ◽  
Isothermal Amplification ◽  
Suspected Case ◽  
Point Of Care Testing ◽  
Loop Mediated Isothermal Amplification

Abstract Background Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains. Methods Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria. Results The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 minutes of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks. Conclusion The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.

Sign in / Sign up

Export Citation Format

Share Document