Electrochemical studies of lateral flow assay test results for procalcitonin detection

2021 ◽  
Author(s):  
Yachana Gupta Gupta ◽  
Kalpana ◽  
Aditya Sharma Ghrera
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Qualitative Analysis ◽  
Test Line ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Quantitative Detection ◽  
Cyclic Voltammograms ◽  
Paper Strip ◽  
Electrochemical Studies

In this study, the lateral flow assay (LFA) has been developed for the detection of bacterial infection (BI) by specific biomarker procalcitonin (PCT), without a need for complicated instrumentations and technical expertise. For the development of the assay, gold nanoparticles (AuNP) and their conjugates with antibodies specific to the model antigen PCT are assessed. Polyclonal antibody (pAb) labelled with gold nanoparticles (AuNP) to obtain the AuNP-pAb complex and the specific monoclonal antibody (mAb) have been dropped at the test zone. This complex is placed over the conjugate line of the LFA strip. In the absence of PCT or the presence of other biomarkers, the test line remained colourless, which revealed the specificity of assay towards PCT among a pool of various analytes. Herein, observations have been made through two different platforms for quantitative and qualitative analysis for the detection of PCT biomarker. The qualitative analysis has been performed on the basis of appearance red color in the test band, while for quantitative analysis, a novel approach has been adopted. Herein, the nitrocellulose membrane (paper strip) is cut out from the LFA strip and used for electrochemical studies under similar solution conditions. Different paper strips presented different cyclic voltammograms (CV) that could be correlated to varying PCT concentrations captured at the test line of the paper strip. The qualitative detection limit for PCT using this LFA was determined to be 2 ng/ml and the quantitative detection limit was 1 ng/ml. The electrochemical response studies of the paper strip by CV technique revealed the sensitivity value of 0.695 mA ng/ml.

scholarly journals Comparison of Single- and Mixed-Sized Gold Nanoparticles on Lateral Flow Assay for Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 209
Author(s):  
Sasima Chotithammakul ◽  
Michael B. Cortie ◽  
Dakrong Pissuwan
Keyword(s):  
Chronic Kidney Disease ◽  
Gold Nanoparticles ◽  
Test Line ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Analytical Performance ◽  
Detection Mechanism ◽  
Multiple Factors ◽  
20 Nm ◽  
Target Analyte

The sensitivity and reproducibility of the lateral flow assay can be influenced by multiple factors, such as the size of gold nanoparticles (GNPs) employed. Here, we evaluated the analytical performance of single-sized and mixed-sized GNPs using a simple lateral flow assay (LFA) platform. This platform was used as a model assay to diagnose albumin levels and demonstrate the analytical performance of single-sized and mixed-sized GNPs in LFA tests. Two sizes of GNPs@anti-bovine serum albumin (BSA) conjugate proteins were mixed at different ratios. The unique optical properties of the GNPs induced a distinguishing color-shedding effect on the single- and mixed-sized GNPs@anti-BSA conjugates interacting with the target analyte BSA spotted on the test line. The use of mixed-sized GNPs@anti-BSA conjugates enhanced signal relative to the 20 nm GNPs, and provided superior stability compared with solely employing the large GNPs (50 nm). The proposed platform in this study could provide an efficient BSA detection mechanism that can be utilized as a model biomarker for confronting chronic kidney disease.

Performance comparison of single and mixed-sized gold nanoparticles on straightforward lateral flow assay for albumin detection

2020 ◽  
Author(s):  
Sasima Chotithammakul ◽  
Dakrong Pissuwan
Keyword(s):  
Gold Nanoparticles ◽  
Signal Amplification ◽  
Test Line ◽  
Testing Procedure ◽  
Performance Comparison ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Analytical Performance ◽  
Detection Mechanism ◽  
Multiple Factors

The sensitivity of the lateral flow assay can be influenced by multiple factors, such as the size of gold nanoparticles (GNPs) employed, which affect the sensitivity and reproducibility of the assay testing procedure. Here, we evaluated the analytical performance of single-sized and mixed-sized GNPs using a simple lateral flow assay (LFA) platform. This platform was used as a model assay to diagnose albumin levels and demonstrate the analytical performance of single-sized and mixed-sized GNPs in LFA tests. Two sizes of GNPs@anti-bovine serum albumin (BSA) conjugate proteins were mixed at different ratios. The unique optical properties of the GNPs induced a distinguishing color-shedding effect on the single and mixed-sized GNPs@anti-BSA conjugates interacting with the target analyte BSA spotted on the test line. The use of mixed-sized GNPs@anti-BSA conjugates enhanced signal amplification, and provided superior stability compared with solely employing the large GNPs (50 nm). The proposed platform in this study could provide an efficient BSA detection mechanism that can be utilized as a biomarker for confronting chronic kidney disease.

Preparation of Glycopolymer-Modified Gold Nanoparticles and a New Approach for a Lateral Flow Assay

2011 ◽  
Vol 84 (5) ◽  
pp. 466-470 ◽  
Author(s):  
Jin Ishii ◽  
Masayuki Toyoshima ◽  
Miyuki Chikae ◽  
Yuzuru Takamura ◽  
Yoshiko Miura
Keyword(s):  
Gold Nanoparticles ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
New Approach

scholarly journals Evaluation of LDBio Aspergillus ICT Lateral Flow Assay for IgG and IgM Antibody Detection in Chronic Pulmonary Aspergillosis

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Elizabeth Stucky Hunter ◽  
Malcolm D. Richardson ◽  
David W. Denning
Keyword(s):  
United Kingdom ◽  
Line Intensity ◽  
Test Line ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Antibody Detection ◽  
Resource Constrained ◽  
Pulmonary Aspergillosis ◽  
Chronic Pulmonary Aspergillosis ◽  
Specific Igg

ABSTRACT Detecting Aspergillus-specific IgG is critical to diagnosing chronic pulmonary aspergillosis (CPA). Existing assays are often cost- and resource-intensive and not compatible with resource-constrained laboratory settings. LDBio Diagnostics has recently commercialized a lateral flow assay based on immunochromatographic technology (ICT) that detects Aspergillus antibodies (IgG and IgM) in less than 30 min, requiring minimal laboratory equipment. A total of 154 CPA patient sera collected at the National Aspergillosis Centre (Manchester, United Kingdom) and control patient sera from the Peninsula Research Bank (Exeter, United Kingdom) were evaluated. Samples were applied to the LDBio Aspergillus ICT lateral flow assay, and results were read both visually and digitally. Results were compared with Aspergillus IgG titers in CPA patients, measured by ImmunoCAP-specific IgG assays. For proven CPA patients versus controls, sensitivity and specificity for the LDBio Aspergillus ICT were 91.6% and 98.0%, respectively. In contrast, the routinely used ImmunoCAP assay exhibited 80.5% sensitivity for the same cohort (cutoff value, 40 mg of antigen-specific antibodies [mgA]/liter). The assay is easy to perform but challenging to read when only a very faint band is present (5/154 samples tested). The ImmunoCAP Aspergillus IgG titer was also compared with the Aspergillus ICT test line intensity or rate of development, with weak to moderate correlations. The Aspergillus ICT lateral flow assay exhibits excellent sensitivity for serological diagnosis of CPA. Quantifying IgG from test line intensity measurements is not reliable. Given the short run time, simplicity, and limited resources needed, the LDBio Aspergillus ICT is a suitable diagnostic tool for CPA in resource-constrained settings.

Development and evaluation of an up-converting phosphor technology-based lateral flow assay for rapid and quantitative detection of aflatoxin B1 in crops

Talanta ◽  
2016 ◽  
Vol 161 ◽  
pp. 297-303 ◽  
Author(s):  
Yong Zhao ◽  
Xiao Liu ◽  
Xiaochen Wang ◽  
Chongyun Sun ◽  
Xinrui Wang ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Quantitative Detection

scholarly journals Lateral-Flow Assay for Rapid Serodiagnosis of Human Leptospirosis

2001 ◽  
Vol 8 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Henk L. Smits ◽  
C. K. Eapen ◽  
Sheela Sugathan ◽  
Mariamma Kuriakose ◽  
M. Hussein Gasem ◽  
...  
Keyword(s):  
Positive Result ◽  
Immunosorbent Assay ◽  
Rapid Detection ◽  
Test Line ◽  
Lateral Flow ◽  
Immunoglobulin M ◽  
Lateral Flow Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Immunoglobulin ◽  
Human Sera

ABSTRACT An assay device for the rapid detection ofLeptospira-specific immunoglobulin M (IgM) antibodies in human sera is presented. The sensitivity (85.8%) and specificity (93.6%) of the assay compared well (91.9% agreement) with those of an IgM enzyme-linked immunosorbent assay routinely used in the serodiagnosis of leptospirosis. The sensitivity of the assay varied with the stage of the disease. The assay uses stabilized components and is simply performed by the addition of serum and sample fluid to the sample well of the assay device. The assay is read after 10 min, and a positive result is obtained when staining of the test line is observed.

Sample Preincubation Strategy for Sensitive and Quantitative Detection of Clenbuterol in Swine Urine Using a Fluorescent Microsphere–Based Immunochromatographic Assay

2014 ◽  
Vol 77 (11) ◽  
pp. 1998-2003 ◽  
Author(s):  
SHENG L. DENG ◽  
SHAN SHAN ◽  
CHAO L. XU ◽  
DAO F. LIU ◽  
YONG H. XIONG ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Rapid Screening ◽  
Immunochromatographic Assay ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fluorescent Microsphere ◽  
Swine Urine ◽  
Relative Standard

We describe an ultrasensitive and quantitative immunochromatographic assay to determine the amount of clenbuterol (CLB) in swine urine. In this study, fluorescein isothiocyanate polystyrene fluorescent microspheres were used as probes. A sample preincubation strategy was introduced to this immunochromatographic assay. Results showed that the strategy evidently improved the sensitivity and accuracy of lateral flow assay. The method was completed in 20 min, and a half-maximal inhibitory concentration of 0.13 μg liter−1 was obtained. The limit of detection of the proposed method to determine CLB in swine urine was 0.01 μg liter−1, which was lower than the limit of detection of immunochromatographic assays without preincubation. Intra-and interday recoveries of spiked swine urine ranged from 85.0 to 107.5%. The relative standard deviation values of the preincubated test strip ranged from 2.7 to 12.5%. Analysis of the CLB in swine urine samples showed that the result obtained from the lateral flow assay is consistent with that obtained from a commercial enzyme-linked immunosorbent assay kit. Our results suggest that the developed fluorescent microsphere–based immunochromatographic assay may be useful as a rapid screening method to detect CLB quantitatively.

scholarly journals Gold Nanobeads with Enhanced Absorbance for Improved Sensitivity in Competitive Lateral Flow Immunoassays

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1488
Author(s):  
Xirui Chen ◽  
Xintao Miao ◽  
Tongtong Ma ◽  
Yuankui Leng ◽  
Liangwen Hao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Inhibitory Concentration ◽  
Fumonisin B1 ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Lateral Flow Immunoassay ◽  
Promising Strategy ◽  
Qualitative Detection ◽  
Better Than

Background: Colloidal gold based lateral flow immunoassay (LFIA) commonly suffers from relatively low detection sensitivity due to the insufficient brightness of conventional gold nanoparticles (AuNPs) with the size of 20–40 nm. Methods: Herein, three kinds of gold nanobeads (GNBs) with the size of 94 nm, 129 nm, and 237 nm, were synthesized by encapsulating numerous hydrophobic AuNPs (10 nm) into polymer matrix. The synthesized GNBs exhibited the enhanced colorimetric signal intensity compared with 20–40 nm AuNPs. The effects of the size of GNBs on the sensitivity of LFIA with competitive format were assessed. Results: The results showed that the LFIA using 129 nm GNBs as amplified signal probes exhibits the best sensitivity for fumonisin B1 (FB1) detection with a cut-off limit (for visual qualitative detection) at 125 ng/mL, a half maximal inhibitory concentration at 11.27 ng/mL, and a detection limit at 1.76 ng/mL for detection of real corn samples, which are 8-, 3.82-, and 2.89-fold better than those of conventional AuNP40-based LFIA, respectively. The developed GNB-LFIA exhibited negligible cross-reactions with other common mycotoxins. In addition, the accuracy, precision, reliability, and practicability were demonstrated by determining real corn samples. Conclusions: All in all, the proposed study provides a promising strategy to enhance the sensitivity of competitive LFIA via using the GNBs as amplified signal probes.

An up-converting phosphor technology-based lateral flow assay for point-of-collection detection of morphine and methamphetamine in saliva

The Analyst ◽  
2018 ◽  
Vol 143 (19) ◽  
pp. 4646-4654 ◽  
Author(s):  
Qiushi Hu ◽  
Qiaozhen Wei ◽  
Pingping Zhang ◽  
Shuang Li ◽  
Lei Xue ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Quantitative Detection

Rapid and quantitative detection of morphine and methamphetamine in saliva with high sensitivity and accuracy by an UPT-LFA.

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