scholarly journals Advantages of Highly Spherical Gold Nanoparticles as Labels for Lateral Flow Immunoassay

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3608
Author(s):  
Nadezhda A. Byzova ◽  
Anatoly V. Zherdev ◽  
Boris N. Khlebtsov ◽  
Andrey M. Burov ◽  
Nikolai G. Khlebtsov ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Troponin I ◽  
Limit Of Detection ◽  
Average Diameter ◽  
Covalent Immobilization ◽  
Lateral Flow ◽  
Antibody Immobilization ◽  
Site Testing ◽  
Spherical Gold Nanoparticles

The use of lateral flow immunoassays (LFIAs) for rapid on-site testing is restricted by their relatively high limit of detection (LoD). One possible way to decrease the LoD is to optimize nanoparticle properties that are used as labels. We compare two types of Au nanoparticles: usual quasispherical gold nanoparticles (C-GNPs), obtained by the Turkevich–Frens method, and superspherical gold nanoparticles (S-GNPs), obtained by a progressive overgrowth technique. Average diameters were 18.6–47.5 nm for C-GNPs and 20.2–90.4 nm for S-GNPs. Cardiomarker troponin I was considered as the target analyte. Adsorption and covalent conjugation with antibodies were tested for both GNP types. For C-GNPs, the minimal LoD was obtained with 33.7 nm nanoparticles, reaching 12.7 ng/mL for covalent immobilization and 9.9 ng/mL for adsorption. The average diameter of S-GNPs varied from 20.2 to 64.5 nm, which resulted in a decrease in LoD for an LFIA of troponin I from 3.4 to 1.2 ng/mL for covalent immobilization and from 2.9 to 2.0 ng/mL for adsorption. Thus, we obtained an 8-fold decrease in LoD (9.9 to 1.2 ng/mL) by using S-GNPs. This effect can be related to more effective antibody immobilization and improved S-GNP optical properties. The obtained results can improve LFIAs for various practically significant analytes.

scholarly journals PEGylated Gold Nanoparticles with Interesting Plasmonic Properties Synthesized Using an Original, Rapid, and Easy-to-Implement Procedure

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ștefan Nițică ◽  
Alin Iulian Moldovan ◽  
Valentin Toma ◽  
Cristian Silviu Moldovan ◽  
Ioana Berindan-Neagoe ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Synthesis Method ◽  
Average Diameter ◽  
Liquid Droplets ◽  
Sers Substrates ◽  
New Class ◽  
One Step ◽  
Short Synthesis ◽  
Spherical Gold Nanoparticles ◽  
Synthesis Procedure

In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis of PEGylated gold nanoparticles (PEG-AuNPs) having a narrow size distribution and very interesting plasmonic properties. Unmodified polyethylene glycol molecules with a molecular weight of 1000 g/mole (PEG1000) have been employed as reducing and capping agents for the synthesis of spherical gold nanoparticles having an average diameter of 35 nm, within a few minutes. The novelty of the herein proposed synthesis method consists in the fact that the synthesis takes place inside of a sealed bottle flask containing aqueous solutions of PEG1000, tetrachloroauric(III) acid (HAuCl4), and NaOH, placed in the center of a microwave oven, capable to provide a very uniform temperature environment. It turned out that, during the very short synthesis procedure (2 minutes), PEG 1000 suffers an oxidative transformation in such a manner that its terminal alcohol groups (-CH2-OH) are transformed in carboxylate ones (-COO−). The as-synthesized PEG-AuNPs possess very interesting plasmonic properties allowing the detection of different molecules by means of SER spectroscopy performed either in liquid droplets or on solid spots. As a consequence of their unique plasmonic properties, the SER spectra acquired using this new class of nanoparticles on different molecules of interest (methylene blue, rhodamine 6G, doxorubicin, and 5-fluorouracil) are highly reproducible, making them ideal candidates for further use as SERS substrates.

scholarly journals Comparison of Nanosized Markers in Lateral Flow Immunoassay of Antibiotic Lincomycin

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 41
Author(s):  
Olga D. Hendrickson ◽  
Kseniya V. Serebrennikova ◽  
Elena A. Zvereva ◽  
Demid S. Popravko ◽  
Anatoly V. Zherdev ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Gold Nanoparticle ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Quantitative Detection ◽  
Site Testing ◽  
Limits Of Detection ◽  
Chemical Contaminants

Improving the sensitivity of the competitive lateral flow immunoassay (LFIA) is important, given the increasing demands for the monitoring of chemical contaminants in food. The choice of nanosized marker is an essential task for improving the LFIA sensitivity. In this study, a CdSe/ZnS quantum dot (QD)-based LFIA combined with a portable reader was developed for rapid and quantitative detection of an antibiotic lincomycin (LIN). The performance of the proposed fluorescence LFIA was compared to the conventional gold nanoparticle (AuNP)-based LFIA realized with the same immunoreagents. The visual cutoff values were 10 ng/mL for AuNP-based LFIA and 20 ng/mL for QD-based LFIA. Furthermore, the instrumental limits of detection have been shown to be comparable for both nanosized markers and amounted to 0.4 ng/mL for AuNPs and 0.2 ng/mL for QDs, respectively. According to the results obtained, both LFIAs may be used for rapid, cost-effective, on-site testing of antibiotics, in particular LIN. However, the QD-based LFIA exhibits lowest limit of detection with the least immunoreagent consumption, which makes it economically beneficial.

scholarly journals Multiple SNPs detection for antimalarial pyrimethamine resistance via allele-specific PCR coupled with gold nanoparticles-based lateral flow biosensor

2020 ◽  
Author(s):  
Tingting Jiang ◽  
Yan Huang ◽  
Weijia Cheng ◽  
Yifei Sun ◽  
Wei Wei ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Genetic Diseases ◽  
Lateral Flow ◽  
Nucleotide Polymorphisms ◽  
Multiple Allele ◽  
Specific Pcr ◽  
Allele Specific ◽  
Allele Specific Pcr

Molecular genotyping holds tremendous potential to detect antimalarial drug resistance (ADR) related to single nucleotide polymorphisms (SNPs). However, it suffers from complicated procedures and expensive instruments. Thus, rapid point-of-care testing (POCT) molecular tools are urgently needed for field survey and clinical use. Herein, a POCT platform consisted of multiple allele-specific PCR (AS-PCR) and gold nanoparticles (AuNPs) based lateral flow biosensor was designed and developed for SNPs detection of Plasmodium falciparum dihydrofolate reductase (pfdhfr) gene related to pyrimethamine resistance. The multiple AS-PCR utilized 3' terminal artificial antepenultimate mismatch and double phosphorothioate-modified allele-specific primers. The duplex PCR amplicons with 5' terminal labeled with biotin and digoxin, respectively, could be recognized by streptavidin (SA)-AuNPs on the conjugate pad and then captured by anti-digoxin antibody through immunoreactions on the test line to produce a golden red line for detection. The system was applied to analyze SNPs in Pfdhfr N51I, C59R, and S108N of 98 clinical isolates from uncomplicated P. falciparum malaria patients. Compared with the results of nested PCR followed Sanger DNA sequencing, the sensitivity is all 97.96% (96/98) for the N51I, C59R, and S108N. For specificity, there were 100% (98/98), 95.92% (94/98), and 100% (98/98) for N51I, C59R, and S108N, respectively. The limit of detection is approximately 200 fg/μl for plasmid DNA as the template and 100 parasites/μl for blood filter paper. The established platform not only offers a powerful tool for molecular surveillance of ADR but also is easily extended to interrelated SNP profiles for infectious diseases and genetic diseases.

scholarly journals An Enhanced Lateral Flow Assay Based on Aptamer–Magnetic Separation and Multifold AuNPs for Ultrasensitive Detection of Salmonella Typhimurium in Milk

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1605
Author(s):  
Pingping Gao ◽  
Lihan Wang ◽  
Yang He ◽  
Yitian Wang ◽  
Xinyan Yang ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Au Nanoparticles ◽  
Limit Of Detection ◽  
High Specificity ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Nucleic Acid Amplification ◽  
Visual Signal ◽  
Magnetic Capture ◽  
Magnetic Enrichment

In this paper, a novel and ultrasensitive lateral flow assay (LFA) based on aptamer–magnetic separation, and multifold Au nanoparticles (AuNPs) was developed for visual detecting Salmonella enterica ser. Typhimurium (S. Typhimurium). The method realized magnetic enrichment and signal transduction via magnetic separation and achieved signal amplification through hybridizing AuNPs–capture probes and AuNPs–amplification probes to form multifold AuNPs. Two different thiolated single-strand DNA (ssDNA) on the AuNPs–capture probe played different roles. One was combined with the AuNPs–amplification probe on the conjugate pad to achieve enhanced signals. The other was connected to transduction ssDNA1 released by aptamer–magnetic capture of S. Typhimurium, and captured by the T-line, forming a positive signal. This method had an excellent linear relationship ranging from 8.6 × 102 CFU/mL to 8.6 × 107 CFU/mL with the limit of detection (LOD) as low as 8.6 × 100 CFU/mL in pure culture. In actual samples, the visual LOD was 4.1 × 102 CFU/mL, which did not carry out nucleic acid amplification and pre-enrichment, increasing three orders of magnitudes than unenhanced assays with single–dose AuNPs and no magnetic separation. Furthermore, the system showed high specificity, having no reaction with other nontarget strains. This visual signal amplificated system would be a potential platform for ultrasensitive monitoring S. Typhimurium in milk samples.

scholarly journals A Novel Application of Electroactive Polyimide Doped with Gold Nanoparticles: As a Chemiresistor Sensor for Hydrogen Sulfide Gas

2019 ◽  
Author(s):  
Lee Marvin G. Padua ◽  
Jui-Ming Yeh ◽  
Karen S. Santiago
Keyword(s):  
Gold Nanoparticles ◽  
Hydrogen Sulfide ◽  
Limit Of Detection ◽  
Average Diameter ◽  
Potential Candidate ◽  
Theoretical Limit ◽  
Work Related ◽  
Diffraction Peaks ◽  
Linear Concentration Range ◽  
Linear Concentration

This research paper presents a new application of electroactive polyimide doped with gold nanoparticles (PI/AuNPs) as a chemiresistor sensor for detecting hydrogen sulfide gas. The synthesis of PI/AuNPs was done in a simple 3-step process of polymerization using the as prepared amine-capped aniline trimer (ACAT), followed by imidization, and doping. Spectral analyses via FTIR, LC-MS and 1H-NMR confirmed the formation of amine-capped aniline trimer with a MW of 288 g mol-1. Comparison of ACAT, BSAA, and PI FTIR spectra showed successful polymerization of the last, while XRD validated the incorporation of metal nanoparticles onto the polymer matrix showing characteristic diffraction peaks corresponding to gold. Furthermore, TEM, and FE-SEM revealed the presence of well-dispersed Au nanoparticles with an average diameter of about 60nm. The electroactive PI/AuNPs-based sensor showed a sensitivity of 0.29% ppm-1 H2S at a linear concentration range of 50 to 300 ppm H2S (r = 0.9777). The theoretical limit of detection was found at 0.142 ppm or 142 ppb H2S gas. The sensor provided a stable response reading at an average response time of 43±5 seconds, which was easily recovered after an average time of 99±5 seconds. The sensor response was highly repeatable and reversible with RSD values of 8.88%, and 8.60%, respectively. Compared with the performance of the conventional conducting polyaniline also doped with gold nanoparticles (PANI/AuNPs), the fabricated electroactive PI/AuNPs exhibited improved sensing performance making it a potential candidate in monitoring H2S in the environment and for work-related safety.

Turn-on Fluorescence Hg2+ Chemosensing Based in a Rhodamine 6G Derivative and Different Sensing Immobilization Approaches

2018 ◽  
Vol 29 ◽  
pp. 57-61
Author(s):  
Arsenio Muñoz de la Peña
Keyword(s):  
Gold Nanoparticles ◽  
Response Time ◽  
Environmental Samples ◽  
Au Nanoparticles ◽  
Rhodamine 6G ◽  
Limit Of Detection ◽  
Sampling Rate ◽  
Practical Applications ◽  
Advantages And Disadvantages ◽  
Turn On

In this study, the advantages and disadvantages of different immobilization approaches, proposed for a luminescent Hg2+chemosensor based in a spirocyclic phenyl-thiosemicarbazide Rhodamine 6G derivative (FC1), are analysed, and a comparative study of the different immobilization protocols is performed. The results demonstrated that the chemosensor is able to detect Hg2+ at ng mL-1 trace levels, with a remarkable selectivity, allowing its determination in biological, toxicological and environmental samples. Methyl methacrylate (MMA) and hydroxyethylmethacrylate (HEMA) polymeric film, electrospinning generated polymeric microfibres, nylon membranes and Au nanoparticles were tested as immobilization materials. The utilization of gold nanoparticles (AuNPs) is the method with the lowest limit of detection (LOD = 0.15 ng mL-1), but the response time is too high for practical use (7 hours). Nylon membranes give a very low detection limit (0.4 ng mL-1) and a practical response time (4 min), being the method of choice for practical applications to determine Hg2+ in aquatic, biological and toxicological samples, at a sampling rate of about 15 samples per hour.

scholarly journals Lateral Flow Immunoassay to Detect the Addition of Beef, Pork, Lamb, and Horse Muscles in Raw Meat Mixtures and Finished Meat Products

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1662
Author(s):  
Elena A. Zvereva ◽  
Demid S. Popravko ◽  
Olga D. Hendrickson ◽  
Natalia L. Vostrikova ◽  
Irina M. Chernukha ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Troponin I ◽  
Meat Products ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Buffer Solution ◽  
Raw Meat ◽  
Muscle Tissues ◽  
Technological Processing ◽  
Efficient Extraction

A lateral flow immunoassay for sensitive detection of skeletal troponin I (TnI) as a specific, thermostable marker of muscle tissue was developed. Due to the antibodies’ choice, the assay specifically detects mammalian TnI (in beef, pork, lamb, and horse) but does not detect bird TnI (in chicken or turkey), thus enabling differentiation of these types of raw meat materials. The assay is based on a sandwich format of the analysis using gold nanoparticles as labels. The time of the assay is 15 min, and the TnI detection limit is 25 ng/mL. A buffer solution is proposed for efficient extraction of TnI from muscle tissues and from finished meat products that have undergone technological processing (smoking–cooking–smoking, cooking and smoking). The possibility of detecting beef addition in minced chicken down to 1% was demonstrated.

Surface Plasmon Effects on Photoluminescence of YAG:Ce3+-Yb3+

2016 ◽  
Vol 98 ◽  
pp. 32-37 ◽  
Author(s):  
Talib Hussain ◽  
Liang Tang ◽  
Hui Qi Ye ◽  
Dong Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Quantum Yield ◽  
Surface Plasmon ◽  
Decay Time ◽  
Au Nanoparticles ◽  
Absorption Peak ◽  
Photoluminescence Band ◽  
Band Ratio ◽  
Spherical Gold Nanoparticles ◽  
Surface Modified

Phosphor materials have fascinating applications in the field of photovoltaic and biosensors but low quantum yield is a major hurdle in their applications. In this paper, the influence of surface plasmon on the photoluminescence is investigated with surface modified YAG:Ce3+-Yb3+ coupled with spherical gold nanoparticles. The YAG:Ce3+-Yb3+ photoluminescence band ratio Yb/Ce rise from 0.25 to 0.32 with the plasmon effects. For the photoluminescence, the decay time of Ce reduces from 31.9 ns to 29.9 ns while for Yb from 54.2 ms to 52.0 ms respectively. Further, the plasmon absorption peak is also observed in the spectra of YAG:Ce3+-Yb3+/Au nanoparticles system. The results indicate that the field inside the phosphors has been modulated with surface plasmon of gold nanoparticles.

scholarly journals Raman Activity of HS-(CH2 ) –NH-Coumarin Molecule Adsorbed on the Surface of Gold Nanostructures with various Morphologies

2021 ◽  
Vol 4 (3) ◽  
Keyword(s):  
Gold Nanoparticles ◽  
Enhancement Factor ◽  
Surface Adsorption ◽  
Average Diameter ◽  
Gold Nanostructures ◽  
Average Particle ◽  
Gold Nanowires ◽  
Particle Sizes ◽  
Nucleation Process ◽  
Spherical Gold Nanoparticles

Synthesis of gold nanowires with an average diameter of 10 nm and length of up to 20 µm was achieved through a three-step heterogeneous nucleation process. Gold nanowires were formed through coalescence of spherical nanocrystals leading to grain growth and subsequently uneven nanowires. Furthermore, the uneven gold nanowires experienced thinning driven by thermodynamics to form relatively even nanowires with smaller diameters. Gold nanowires showed enhanced Raman activity in respect to enhancement factor than respective spherical gold nanoparticles with average particle sizes of 14 nm, 30 nm and 40 nm. The better Raman activity of gold nanowires with respect to spherical morphology was attributed to how they adsorb Raman active molecules, which are surface adsorption and network entanglement.

scholarly journals A Novel Application of Electroactive Polyimide Doped with Gold Nanoparticles: As a Chemiresistor Sensor for Hydrogen Sulfide Gas

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1918 ◽  
Author(s):  
Lee Marvin G. Padua ◽  
Jui-Ming Yeh ◽  
Karen S. Santiago
Keyword(s):  
Gold Nanoparticles ◽  
Hydrogen Sulfide ◽  
Limit Of Detection ◽  
Average Diameter ◽  
Potential Candidate ◽  
Theoretical Limit ◽  
Work Related ◽  
Diffraction Peaks ◽  
Linear Concentration Range ◽  
Linear Concentration

This research paper presents a new application of electroactive polyimide doped with gold nanoparticles (PI/AuNPs) as a chemiresistor sensor for detecting hydrogen sulfide gas. The synthesis of PI/AuNPs was done in a simple 3-step process of polymerization using the as prepared amine-capped aniline trimer (ACAT), followed by imidization, and doping. Spectral analyses via FTIR, LC-MS and 1H-NMR confirmed the formation of amine-capped aniline trimer with a MW of 288 g mol−1. Comparison of ACAT, BSAA, and PI FTIR spectra showed successful polymerization of the last, while XRD validated the incorporation of metal nanoparticles onto the polymer matrix, showing characteristic diffraction peaks corresponding to gold. Furthermore, TEM, and FE-SEM revealed the presence of well-dispersed Au nanoparticles with an average diameter of about 60 nm. The electroactive PI/AuNPs-based sensor showed a sensitivity of 0.29% ppm−1 H2S at a linear concentration range of 50 to 300 ppm H2S (r = 0.9777). The theoretical limit of detection was found at 0.142 ppm or 142 ppb H2S gas. The sensor provided a stable response reading at an average response time of 43 ± 5 s, which was easily recovered after an average time of 99 ± 5 s. The sensor response was highly repeatable and reversible, with RSD values of 8.88%, and 8.60%, respectively. Compared with the performance of the conventional conducting polyaniline also doped with gold nanoparticles (PANI/AuNPs), the fabricated electroactive PI/AuNPs exhibited improved sensing performance making it a potential candidate in monitoring H2S in the environment and for work-related safety.

Sign in / Sign up

Export Citation Format

Share Document