Novel Latex Microsphere Immunochromatographic Assay for Rapid Detection of Cadmium Ion in Asparagus

Recently, concerns about heavy metal cadmium ion (Cd2+) residue in asparagus have been frequently reported, and there is an urgent need to develop an effective, sensitive, and rapid detection method for Cd2+. In this study, we innovatively combined molecular microbiology to carry out the comparative screening of Cd2+ chelators in a green, efficient, and specific way. The knock-out putative copper-transporter gene (pca1Δ) yeast strain with high sensitivity to Cd2+ was first used to screen the Cd2+ chelator, and the optimum chelator 1-(4-Isothiocyanatobenzyl)ethylenediamine-N,N,N,N′-tetraacetic acid (ITCBE) was obtained. Additionally, a rapid latex microsphere immunochromatographic assay (LMIA) was developed, based on the obtained monoclonal antibody (mAb) with high specificity and high affinity (affinity constant Ka = 1.83 × 1010 L/mol), to detect Cd2+ in asparagus. The 50% inhibitive concentration (IC50) of test strip was measured to be 0.2 ng/mL, and the limit of detection (IC10) for qualitative (LOD, for visual observation) and quantitative detection (LOQ, for data simulation) of the test strip was 2 ng/mL and 0.054 ng/mL, respectively. In all, the developed mAb-based LMIA shows a great potential for monitoring Cd2+ in asparagus, even in vegetable samples.

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Disposable silicon-based all-in-one micro-qPCR for rapid on-site detection of pathogens

Nature Communications ◽

10.1038/s41467-020-19911-6 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Estefania Nunez-Bajo ◽

Alexander Silva Pinto Collins ◽

Michael Kasimatis ◽

Yasin Cotur ◽

Tarek Asfour ◽

...

Keyword(s):

Real Time ◽

Limit Of Detection ◽

Low Cost ◽

High Specificity ◽

Rapid Screening ◽

Quantitative Detection ◽

The Novel ◽

Novel Coronavirus ◽

Silicon Based ◽

Specific Sequences

AbstractRapid screening and low-cost diagnosis play a crucial role in choosing the correct course of intervention when dealing with highly infectious pathogens. This is especially important if the disease-causing agent has no effective treatment, such as the novel coronavirus SARS-CoV-2, and shows no or similar symptoms to other common infections. Here, we report a disposable silicon-based integrated Point-of-Need transducer (TriSilix) for real-time quantitative detection of pathogen-specific sequences of nucleic acids. TriSilix can be produced at wafer-scale in a standard laboratory (37 chips of 10 × 10 × 0.65 mm in size can be produced in 7 h, costing ~0.35 USD per device). We are able to quantitatively detect a 563 bp fragment of genomic DNA of Mycobacterium avium subspecies paratuberculosis through real-time PCR with a limit-of-detection of 20 fg, equivalent to a single bacterium, at the 35th cycle. Using TriSilix, we also detect the cDNA from SARS-CoV-2 (1 pg) with high specificity against SARS-CoV (2003).

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Nanogravimetric and Optical Characterizations of Thrombin Interaction with a Self-Assembled Thiolated Aptamer

Journal of Sensors ◽

10.1155/2016/3561863 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Jane Politi ◽

Ilaria Rea ◽

Fabrizia Nici ◽

Principia Dardano ◽

Monica Terracciano ◽

...

Keyword(s):

Limit Of Detection ◽

High Specificity ◽

Medical Diagnostics ◽

Affinity Constant ◽

Label Free ◽

Gold Substrate ◽

System Sensitivity ◽

All Optical ◽

Thiolated Aptamer

Efficient biorecognition of thrombin (TB), a serine protease with crucial role in physiological and pathological blood coagulation, is a hot topic in medical diagnostics. In this work, we investigate the ability of synthetic thrombin aptamer (TBA), immobilized on a gold substrate, to bind thrombin by two different label-free techniques: the quartz crystal microbalance (QCM) and the spectroscopic ellipsometry (SE). By QCM characterization in the range from 20 to 110 nM, we demonstrate high specificity of TBA-TB interaction and determine affinity constant (Kd) of17.7±0.3 nM, system sensitivity of0.42±0.03 Hz nM−1, and limit of detection (LOD) of240±20 pM. The interaction between TBA and TB is also investigated by SE, an all-optical method, by quantifying the thickness increase of the TBA film assembled on gold substrate. AFM characterization of TBA and TB molecules deposited on flat silicon surface is also supplied.

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Fluorescent fullerene nanoparticle-based lateral flow immunochromatographic assay for rapid quantitative detection of C-reactive protein

Nano Convergence ◽

10.1186/s40580-019-0207-0 ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Kyung Mi Park ◽

Da Jung Chung ◽

Mijin Choi ◽

Taejoon Kang ◽

Jinyoung Jeong

Keyword(s):

Chemical Species ◽

Test Strip ◽

Disease Diagnosis ◽

Lateral Flow ◽

Immunochromatographic Assay ◽

Quantitative Detection ◽

C Reactive Protein ◽

Reactive Protein ◽

Diagnosis And Prognosis ◽

Lateral Flow Immunochromatographic Assay

Abstract A fluorescent fullerene nanoparticle (NP)-based lateral flow immunochromatographic assay (LFIA) was developed for the rapid and quantitative detection of C-reactive protein (CRP) in serum. The polyclonal CRP-antibody-conjugated fullerene NPs were simply prepared by 1-ethyl-3-(3-dimethyllaminopropyl)-carbodiimide hydrochloride coupling after carboxylation of fluorescent fullerene NPs. By applying the CRP-antibody-conjugated fullerene NPs to a lateral flow test strip, quantitative analysis of CRP in serum was possible at a concentration range of 0.1–10 ng/ml within 15 min. We anticipate that this novel fluorescent fullerene NP-based LFIA can be useful for the rapid and accurate sensing of biological and chemical species, contributing to the disease diagnosis and prognosis, environmental monitoring, and food safety.

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Ultrasensitive surface-enhanced Raman scattering detection in common fluids

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1518980113 ◽

2015 ◽

Vol 113 (2) ◽

pp. 268-273 ◽

Cited By ~ 346

Author(s):

Shikuan Yang ◽

Xianming Dai ◽

Birgitt Boschitsch Stogin ◽

Tak-Sing Wong

Keyword(s):

Raman Scattering ◽

Limit Of Detection ◽

High Specificity ◽

Surface Enhanced Raman Scattering ◽

Mapping Technique ◽

Quantitative Detection ◽

Specificity And Sensitivity ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Enhanced Raman Scattering

Detecting target analytes with high specificity and sensitivity in any fluid is of fundamental importance to analytical science and technology. Surface-enhanced Raman scattering (SERS) has proven to be capable of detecting single molecules with high specificity, but achieving single-molecule sensitivity in any highly diluted solutions remains a challenge. Here we demonstrate a universal platform that allows for the enrichment and delivery of analytes into the SERS-sensitive sites in both aqueous and nonaqueous fluids, and its subsequent quantitative detection of Rhodamine 6G (R6G) down to ∼75 fM level (10−15 mol⋅L−1). Our platform, termed slippery liquid-infused porous surface-enhanced Raman scattering (SLIPSERS), is based on a slippery, omniphobic substrate that enables the complete concentration of analytes and SERS substrates (e.g., Au nanoparticles) within an evaporating liquid droplet. Combining our SLIPSERS platform with a SERS mapping technique, we have systematically quantified the probability, p(c), of detecting R6G molecules at concentrations c ranging from 750 fM (p > 90%) down to 75 aM (10−18 mol⋅L−1) levels (p ≤ 1.4%). The ability to detect analytes down to attomolar level is the lowest limit of detection for any SERS-based detection reported thus far. We have shown that analytes present in liquid, solid, or air phases can be extracted using a suitable liquid solvent and subsequently detected through SLIPSERS. Based on this platform, we have further demonstrated ultrasensitive detection of chemical and biological molecules as well as environmental contaminants within a broad range of common fluids for potential applications related to analytical chemistry, molecular diagnostics, environmental monitoring, and national security.

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

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-086 ◽

2014 ◽

Vol 77 (11) ◽

pp. 1998-2003 ◽

Cited By ~ 18

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.

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Polystyrene Microsphere-Based Immunochromatographic Assay for Detection of Aflatoxin B1 in Maize

Biosensors ◽

10.3390/bios11060200 ◽

2021 ◽

Vol 11 (6) ◽

pp. 200

Author(s):

Jin Wang ◽

Xiangmei Li ◽

Xing Shen ◽

Ang Zhang ◽

Jinxiu Liu ◽

...

Keyword(s):

Aflatoxin B1 ◽

Limit Of Detection ◽

Point Of Care ◽

Immunochromatographic Assay ◽

Quantitative Detection ◽

Point Of Care Testing ◽

Polystyrene Microsphere ◽

Accuracy And Precision ◽

Wide Range ◽

Liquid Chromatography Tandem Mass

Aflatoxin B1 (AFB1), a mycotoxin, is hepatotoxic, carcinogenic, and nephrotoxic in humans and animals, and contaminate a wide range of maize. In this study, an immunochromatographic assay (ICA) based on polystyrene microspheres (PMs) was developed for sensitive and quantitative detection of AFB1 in maize. The amounts of PMs, the condition for activating carboxyl groups of PMs, the amount of monoclonal antibody (mAb), and the volume of the immune probe were optimized to enhance the performance PMs-ICA for point-of-care testing of AFB1 in maize. The PMs-ICA showed the cut-off value of 1 ng/mL in phosphate buffer (PB) and 6 µg/kg in maize samples, respectively. The quantitative limit of detection (qLOD) was 0.27 and 1.43 µg/kg in PB and maize samples, respectively. The accuracy and precision of the PMs-ICA were evaluated by analysis of spiked maize samples with recoveries of 96.0% to 107.6% with coefficients of variation below 10%. In addition, the reliability of PMs-ICA was confirmed by the liquid chromatography-tandem mass spectrometry method. The results indicated that the PMs-ICA could be used as a sensitive, simple, rapid point-of-care testing of AFB1 in maize.

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Rapid Kinetic Fingerprinting of Single Nucleic Acid Molecules by a FRET-based Dynamic Nanosensor

10.1101/2021.04.06.438627 ◽

2021 ◽

Author(s):

Kunal Khanna ◽

Shankar Mandal ◽

Aaron T Blanchard ◽

Muneesh Tewari ◽

Alexander Johnson-Buck ◽

...

Keyword(s):

Single Molecule ◽

Rapid Detection ◽

Limit Of Detection ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

High Specificity ◽

Digital Pcr ◽

Clinical Diagnostics ◽

Fluorescent Detection ◽

Single Molecule Level

Biofluids contain cell-free nucleic acids such as microRNAs (miRNAs) and circulating tumor-derived DNAs (ctDNAs) that have emerged as promising disease biomarkers. Conventional detection of these biomarkers by digital PCR and next generation sequencing, although highly sensitive, requires time-consuming extraction and amplification steps that increase the risk of sample loss and cross-contamination, respectively. To achieve the direct, rapid detection of miRNAs and ctDNAs with near-perfect specificity and single-molecule level sensitivity, we herein describe an accelerated amplification-free single-molecule kinetic fingerprinting. This approach, termed intramolecular single-molecule recognition through equilibrium Poisson sampling (iSiMREPS), exploits a dynamic DNA nanosensor comprising a surface anchor and a pair of fluorescent detection probes: one probe captures individual target molecules onto the surface, while the other transiently interrogates them to generate kinetic fingerprints by intramolecular sin-gle-molecule Forster resonance energy transfer (smFRET). Formamide is used to further accelerate the kinetics of probe-target interactions and fingerprinting, while background signals are reduced by removing non-target-bound probes from the surface using toehold-mediated strand displacement. We show that iSiMREPS can detect in as little as 10 seconds two distinct, promising cancer biomarkers, miR-141 and a common EGFR exon 19 deletion, reaching a limit of detection (LOD) of ~3 fM and a mutant allele fraction among excess wild-type as low as 1 in 1 million, or 0.0001%. We anticipate that iSiMREPS will find utility in research and clinical diagnostics based on its features of rapid detection, high specificity, sensitivity, and generalizability.

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Foundation and Clinical Evaluation of a New Method for Detecting SARS-CoV-2 Antigen by Fluorescent Microsphere Immunochromatography

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.553837 ◽

2020 ◽

Vol 10 ◽

Author(s):

Chunyan Zhang ◽

Lei Zhou ◽

Kang Du ◽

Ying Zhang ◽

Jing Wang ◽

...

Keyword(s):

Clinical Evaluation ◽

Rapid Detection ◽

Limit Of Detection ◽

Test Strip ◽

Healthy Controls ◽

Percentage Agreement ◽

N Protein ◽

Fluorescent Microsphere ◽

Methodological Evaluation ◽

Detection Reagent

PurposeTo develop a rapid detection reagent for SARS-CoV-2 antigen for the auxiliary diagnosis of new coronary pneumonia (COVID-19), and perform the methodological evaluation and clinical evaluation of the reagent.MethodSARS-CoV-2 N-protein test strip was created by combining fluorescent microsphere labeling technology and immunochromatographic technology, based on the principle of double antibody sandwich. Then we evaluated the analytical capability and clinical application of the strips.ResultThe limit of detection of the strips for recombinant N protein was 100 ng/ml and for activated SARS -CoV-2 virus was 1 × 103 TCID50/ml. The strips also have high analytical specificity and anti-interference capability. According to the predetermined cut-off value, the specificity of the test strip in healthy controls and patients with other respiratory disease was 100.00 and 97.29%, the sensitivity in COVID-19 cases at progress stage and cured stage was 67.15 and 7.02%. The positive percentage agreement and negative percentage agreement of antigen strip to RNA test were 83.16 and 94.45%.ConclusionSARS-CoV-2 fluorescence immunochromatographic test strip can achieve fast, sensitive and accurate detection, which can meet the clinical requirements for rapid detection of viruses on the spot.

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Quantitative and rapid detection of microcystin-LR using time-resolved fluorescence immunochromatographic assay based on europium nanospheres

Analytical Methods ◽

10.1039/c7ay02036h ◽

2017 ◽

Vol 9 (45) ◽

pp. 6430-6434 ◽

Cited By ~ 8

Author(s):

Yi Zhang ◽

Xin-Liang Ding ◽

Ming-Ming Guo ◽

Ting-Ting Han ◽

Zi-Jian Huang ◽

...

Keyword(s):

Rapid Detection ◽

Immunochromatographic Assay ◽

Quantitative Detection ◽

Time Resolved Fluorescence ◽

Time Resolved

In the present study, a novel time-resolved fluorescence immunochromatographic assay was established for the rapid quantitative detection of microcystin-leucine arginine (MC-LR).

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A novel fluorescence immunochromatographic assay strip for the diagnosis of schistosomiasis japonica

Parasites & Vectors ◽

10.1186/s13071-020-04511-6 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Yuanxi Shen ◽

Rongyi Ji ◽

Rui Chai ◽

Nana Yuan ◽

Jiyue Zhang ◽

...

Keyword(s):

Recombinant Protein ◽

Schistosoma Japonicum ◽

Limit Of Detection ◽

Domestic Animals ◽

Binding Activity ◽

Schistosomiasis Japonica ◽

Immunochromatographic Assay ◽

Affinity Constant ◽

Restriction Enzyme Digestion ◽

Control Line

Abstract Background Schistosomiasis japonica is a severe zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. Surveillance and diagnosis play key roles in schistosomiasis control; however, current techniques for the surveillance and diagnosis of the disease have limitations. In this study, we developed a novel fluorescence immunochromatographic assay (FICA) strip to detect anti-Schistosoma japonicum antibodies in host serum. Methods A FICA strip was developed for the diagnosis of Schistosoma japonicum in domestic animals. Streptococcus protein G (SPG) and soluble egg antigen (SEA) were transferred onto a nitrocellulose (NC) membrane to form the control line (C) and the test line (T), respectively. With fluorescence activity as well as binding activity to multispecies IgG, the recombinant protein rSPG-RFP was expressed and employed as an antibody indicator in the FICA strips. Results The dual gene fusion plasmid was verified by PCR and restriction enzyme digestion. The expressed recombinant protein was 39.72 kDa in size, which was consistent with the predicted molecular weight. The western blot results showed binding activity between rSPG-RFP and IgGs from different hosts. Fluorescence microscopy also showed the fluorescence activity of the protein present. The affinity constant (Ka) values of rSPG-RFP with rabbit, donkey, mouse and goat IgG were 1.9 × 105, 4.1 × 105, 1.7 × 105 and 5.4 × 105, respectively. Moreover, based on the recombinant protein, the test strip for detecting S. japonicum in buffaloes could distinguish positive from negative serum. The lower limit of detection of the FICA strip was 1:10,000. Compared with ELISA, the FICA strips exhibited similar results in the diagnosis of infection in clinical bovine serum samples, with a kappa value of 0.9660 and P < 0.01. The cross-reactivities of the FICA strips with Haemonchus contortus and Schistosoma turkestanicum (30.15% and 91.66%, respectively) were higher than those of ELISA (26.98% and 87.5%, respectively). Conclusions Based on the rSPG-RFP protein that we developed, strip detection can be completed within 15 min. Heightened sensitivity allows the strip to accurately identify schistosome antibodies in serum. In conclusion, this method is convenient, feasible, rapid and effective for detecting S. japonicum.

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