Ultrasensitive SERS-Based Immunoassay of Tumor Marker in Serum Using Au–Ag Alloy Nanoparticles and Ag/AgBr Hybrid Nanostructure

Ultrasensitive detection of alpha-fetoprotein (AFP) is critical for the early diagnosis of liver cancer. In this work, a novel surface-enhanced Raman scattering (SERS)-based immunoassay complex has been successfully developed for the detection of AFP by using the Au-Ag alloy nanoparticals and the Ag/AgBr hybrid nanostructure. As the typical bimetal or metal/semiconductor plasmonic materials, besides the strong SERS enhancement characteristics, the Au-Ag alloy nanoparticals exhibit excellent monodispersity and the Ag/AgBr hybrid nanostructure demonstrates good stability. The experimental results show that the SERS-based immunoassay of AFP presents a low limit of detection of 1.86[Formula: see text]fg/mL and a broad dynamic range from 2[Formula: see text]fg/mL to 0.8[Formula: see text][Formula: see text]g/mL. Furthermore, the clinical applicability of the proposed SERS-based immunoassay has been assessed by the detection of AFP in the human serum samples of cancer patient and healthy person. The test data are consistent well with that of chemiluminescence immunoassay (CLIA) in the relative errors of [Formula: see text]8.82–8.06% and show better detection sensitivity. It reveals that the proposed immunoassay protocol is significant for giving insight into the design of ultrasensitive biosensor and the point-of-care testing of cancers.

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Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

10.26434/chemrxiv.5662315.v1 ◽

2017 ◽

Author(s):

Bo Tian ◽

Peter Svedlindh ◽

Mattias Strömberg ◽

Erik Wetterskog

Keyword(s):

Magnetic Nanoparticles ◽

Ferromagnetic Resonance ◽

Limit Of Detection ◽

Point Of Care ◽

Rolling Circle Amplification ◽

Resonance Field ◽

Isothermal Amplification ◽

Detection Sensitivity ◽

Serum Samples ◽

Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, i.e., rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg2P2O7 (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.

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Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

10.26434/chemrxiv.5662315 ◽

2017 ◽

Author(s):

Bo Tian ◽

Peter Svedlindh ◽

Mattias Strömberg ◽

Erik Wetterskog

Keyword(s):

Magnetic Nanoparticles ◽

Ferromagnetic Resonance ◽

Limit Of Detection ◽

Point Of Care ◽

Rolling Circle Amplification ◽

Resonance Field ◽

Isothermal Amplification ◽

Detection Sensitivity ◽

Serum Samples ◽

Rolling Circle

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Establishment of Simultaneous Detection and Quantitation of HCVRNA by Third Generation Intercalating Dye Real-time PCR

IIUM Medical Journal Malaysia ◽

10.31436/imjm.v17i1.843 ◽

2018 ◽

Vol 17 (1) ◽

Author(s):

Akrahm M. Saleh Habil ◽

Hairul Aini Hamzah ◽

Muhammad Imad Al-Deen Mustafa ◽

Norlelawati A. Talib ◽

Siti Nurul Fazlin Abdul Rahman

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Dynamic Range ◽

Limit Of Detection ◽

False Negative ◽

Simultaneous Detection ◽

Pcr Amplification ◽

Serum Samples ◽

Negative Results ◽

Broad Dynamic Range

Introduction: Rapid quantification of hepatitis C virus is helpful in determining and monitoring of the disease progression and nature of the virus replication. The aim of the present study was to establish a fast, specific and sensitive tool for HCVRNA quantification. Materials and Methods: A total of 50 serum samples, comprising of 40 HCV-positive and 10 HCV-negative, were included in our study. RNA was extracted, reverse transcribed, and then subjected to real-time PCR amplification. Real-time PCR using EvaGreen dye and primers targeting a 5’UTR was carried out. Reference samples with known viral load were treated similarly to the unknown samples and used to create the standard curves. Results: Our method showed a high level of analytical specificity and accuracy, with a low limit of detection (~2 IU/ml). It yielded repeatable results with less than 4% of intra- assay variation. The assay covered a broad dynamic range of quantification, ranging from 0.34 to 6 log IU/ml. The diagnostic sensitivity, specificity, and accuracy were all 100%, indicating neither false positive nor false negative results were obtained. Conclusion: The developed real time PCR using EvaGreen dye has demonstrated a highly analytical and diagnostic performance for HCV quantification, suggesting its potential in clinical diagnosis and management.

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A tandem giant magnetoresistance assay for one-shot quantification of clinically relevant concentrations of N-terminal pro-B-type natriuretic peptide in human blood

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03227-5 ◽

2021 ◽

Author(s):

Fanda Meng ◽

Weisong Huo ◽

Jie Lian ◽

Lei Zhang ◽

Xizeng Shi ◽

...

Keyword(s):

Detection Limit ◽

Giant Magnetoresistance ◽

Dynamic Range ◽

Point Of Care ◽

Sample Volume ◽

Small Sample ◽

Broad Dynamic Range ◽

Gmr Sensors ◽

Gmr Sensor ◽

Sample Volume Requirement

AbstractWe report a microfluidic sandwich immunoassay constructed around a dual-giant magnetoresistance (GMR) sensor array to quantify the heart failure biomarker NT-proBNP in human plasma at the clinically relevant concentration levels between 15 pg/mL and 40 ng/mL. The broad dynamic range was achieved by differential coating of two identical GMR sensors operated in tandem, and combining two standard curves. The detection limit was determined as 5 pg/mL. The assay, involving 53 plasma samples from patients with different cardiovascular diseases, was validated against the Roche Cobas e411 analyzer. The salient features of this system are its wide concentration range, low detection limit, small sample volume requirement (50 μL), and the need for a short measurement time of 15 min, making it a prospective candidate for practical use in point of care analysis.

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Multitarget, quantitative nanoplasmonic electrical field-enhanced resonating device (NE2RD) for diagnostics

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1510824112 ◽

2015 ◽

Vol 112 (32) ◽

pp. E4354-E4363 ◽

Cited By ~ 44

Author(s):

Fatih Inci ◽

Chiara Filippini ◽

Murat Baday ◽

Mehmet Ozgun Ozen ◽

Semih Calamak ◽

...

Keyword(s):

Dynamic Range ◽

Point Of Care ◽

Medical Diagnostics ◽

Clinical Samples ◽

Label Free ◽

Protein Biomarkers ◽

Electrical Field ◽

Color Changes ◽

Sensing Platform ◽

Broad Dynamic Range

Recent advances in biosensing technologies present great potential for medical diagnostics, thus improving clinical decisions. However, creating a label-free general sensing platform capable of detecting multiple biotargets in various clinical specimens over a wide dynamic range, without lengthy sample-processing steps, remains a considerable challenge. In practice, these barriers prevent broad applications in clinics and at patients’ homes. Here, we demonstrate the nanoplasmonic electrical field-enhanced resonating device (NE2RD), which addresses all these impediments on a single platform. The NE2RD employs an immunodetection assay to capture biotargets, and precisely measures spectral color changes by their wavelength and extinction intensity shifts in nanoparticles without prior sample labeling or preprocessing. We present through multiple examples, a label-free, quantitative, portable, multitarget platform by rapidly detecting various protein biomarkers, drugs, protein allergens, bacteria, eukaryotic cells, and distinct viruses. The linear dynamic range of NE2RD is five orders of magnitude broader than ELISA, with a sensitivity down to 400 fg/mL This range and sensitivity are achieved by self-assembling gold nanoparticles to generate hot spots on a 3D-oriented substrate for ultrasensitive measurements. We demonstrate that this precise platform handles multiple clinical samples such as whole blood, serum, and saliva without sample preprocessing under diverse conditions of temperature, pH, and ionic strength. The NE2RD’s broad dynamic range, detection limit, and portability integrated with a disposable fluidic chip have broad applications, potentially enabling the transition toward precision medicine at the point-of-care or primary care settings and at patients’ homes.

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Rapid Detection of Bacillus anthracis Bloodstream Infections by Use of a Novel Assay in the GeneXpert System

Journal of Clinical Microbiology ◽

10.1128/jcm.00466-17 ◽

2017 ◽

Vol 55 (10) ◽

pp. 2964-2971 ◽

Cited By ~ 4

Author(s):

Padmapriya P. Banada ◽

Srinidhi Deshpande ◽

Riccardo Russo ◽

Eric Singleton ◽

Darshini Shah ◽

...

Keyword(s):

Bacillus Anthracis ◽

Dynamic Range ◽

Limit Of Detection ◽

Point Of Care ◽

Severe Disease ◽

Automated System ◽

Bacterial Isolates ◽

Sample Processing ◽

Blood Samples ◽

Content Type

ABSTRACT Bacillus anthracis is a tier 1 select agent with the potential to quickly cause severe disease. Rapid identification of this pathogen may accelerate treatment and reduce mortality in the event of a bioterrorism attack. We developed a rapid and sensitive assay to detect B. anthracis bacteremia using a system that is suitable for point-of-care testing. A filter-based cartridge that included both sample processing and PCR amplification functions was loaded with all reagents needed for sample processing and multiplex nested PCR. The assay limit of detection (LOD) and dynamic range were determined by spiking B. anthracis DNA into individual PCR mixtures and B. anthracis CFU into human blood. One-milliliter blood samples were added to the filter-based detection cartridge and tested for B. anthracis on a GeneXpert instrument. Assay specificity was determined by testing blood spiked with non-anthrax bacterial isolates or by testing blood samples drawn from patients with concurrent non- B. anthracis bacteremia or nonbacteremic controls. The assay LODs were 5 genome equivalents per reaction and 10 CFU/ml blood for both the B. anthracis Sterne and V1B strains. There was a 6-log 10 dynamic range. Assay specificity was 100% for tests of non- B. anthracis bacterial isolates and patient blood samples. Assay time was less than 90 min. This automated system suitable for point-of-care detection rapidly identifies B. anthracis directly from blood with high sensitivity. This assay might lead to early detection and more rapid therapy in the event of a bioterrorism attack.

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Reusable, Noninvasive, and Sensitive Fluorescence Enhanced ZnO-Nanorod-Based Microarrays for Quantitative Detection of AFP in Human Serum

BioMed Research International ◽

10.1155/2021/9916909 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Saima Rafique ◽

Farukh Kiyani ◽

Sumbal Jawaid ◽

Rubina Nasir ◽

Mahmoosh Ahmad ◽

...

Keyword(s):

Human Serum ◽

Dynamic Range ◽

Limit Of Detection ◽

Zno Nanorods ◽

Protein Microarrays ◽

Great Promise ◽

Quantitative Detection ◽

Zno Nanorod ◽

Serum Samples ◽

Protein Assay

The fabrication of sensitive protein microarrays such as PCR used in DNA microarray is challenging due to lack of signal amplification. The development of microarrays is utilized to improve the sensitivity and limitations of detection towards primal cancer detection. The sensitivity is enhanced by the use of ZnO-nanorods and is investigated as a substrate which enhance the florescent signal to diagnose the hepatocellular carcinoma (HCC) at early stages. The substrate for deposition of ZnO-nanorods is prepared by the conventional chemical bath deposition method. The resultant highly dense ZnO-nanorods enhance the fluorescent signal 7.2 times as compared to the substrate without ZnO-nanorods. The microarray showed sensitivity of 1504.7 ng ml-1 and limit of detection of 0.1 pg ml-1 in wide dynamic range of 0.05 pg-10 μg ml-1 for alpha fetoprotein (AFP) detection in 10% human serum. This immunoassay was successfully applied for human serum samples to detect tumor marker with good recoveries. The ZnO-nanorod substrate is a simple protein microarray which showed a great promise for developing a low-cost, sensitive, and high-throughput protein assay platform for several applications in both fundamental research and clinical diagnosis.

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Hydrophobic Paper-Based SERS Sensor Using Gold Nanoparticles Arranged on Graphene Oxide Flakes

Sensors ◽

10.3390/s19245471 ◽

2019 ◽

Vol 19 (24) ◽

pp. 5471 ◽

Cited By ~ 3

Author(s):

Dong-Jin Lee ◽

Dae Yu Kim

Keyword(s):

Gold Nanoparticles ◽

Graphene Oxide ◽

Limit Of Detection ◽

Point Of Care ◽

Hydrophobic Surface ◽

Sers Substrate ◽

High Porosity ◽

Paper Substrate ◽

Surface Enhanced Raman ◽

Hydrophobic Paper

Paper-based surface-enhanced Raman scattering (SERS) sensors have garnered much attention in the past decade owing to their ubiquity, ease of fabrication, and environmentally friendly substrate. The main drawbacks of a paper substrate for a SERS sensor are its high porosity, inherent hygroscopic nature, and hydrophilic surface property, which reduce the sensitivity and reproducibility of the SERS sensor. Here, we propose a simple, quick, convenient, and economical method for hydrophilic to hydrophobic surface modification of paper, while enhancing its mechanical and moisture-resistant properties. The hydrophobic paper (h-paper) was obtained by spin-coating diluted polydimethylsiloxane (PDMS) solution onto the filter paper, resulting in h-paper with an increased contact angle of up to ≈130°. To complete the h-paper-based SERS substrate, gold nanoparticles arranged on graphene oxide (AuNPs@GO) were synthesized using UV photoreduction, followed by drop-casting of AuNPs@GO solution on the h-paper substrate. The enhancement of the SERS signal was then assessed by attaching a rhodamine 6G (R6G) molecule as a Raman probe material to the h-paper-based SERS substrate. The limit of detection was 10 nM with an R2 of 0.966. The presented SERS sensor was also tested to detect a thiram at the micromolar level. We expect that our proposed AuNPs@GO/h-paper-based SERS sensor could be applied to point-of-care diagnostics applications in daily life and in spacecraft.

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Sensitivity of the STAT-VIEW rapid self-test and implications for use during acute HIV infection

Sexually Transmitted Infections ◽

10.1136/sextrans-2017-053131 ◽

2017 ◽

Vol 94 (7) ◽

pp. 475-478 ◽

Cited By ~ 1

Author(s):

Narjis Boukli ◽

Anders Boyd ◽

Noémie Wendremaire ◽

Pierre-Marie Girard ◽

Julie Bottero ◽

...

Keyword(s):

Hiv Infection ◽

Point Of Care ◽

Rapid Test ◽

Detection Sensitivity ◽

Serum Samples ◽

Acute Hiv Infection ◽

Hiv Rna ◽

Rapid Tests ◽

Acute Hiv ◽

Self Test

ObjectivesHIV testing is an important step towards diminishing incident infections. Rapid self-tests whose use is becoming more common in France could help increase access to testing, yet could fail to diagnose HIV during acute HIV infection (AHI). The aim of the present study was to evaluate HIV-detection sensitivity of a commonly used rapid self-test (STAT-VIEW HIV1/2), compared with another point-of-care rapid test (INSTI), among patients presenting with AHI.MethodsIndividuals tested at Saint-Antoine Hospital (Paris, France) with negative or indeterminate western blot (WB) results and detectable HIV-RNA were included. Rapid tests were performed retrospectively on stored serum. Patients with and without reactive rapid tests were compared, while probability of having a reactive test was modelled across infection duration using logistic regression.ResultsOf the 40 patients with AHI, 23 (57.5%) had a reactive STAT-VIEW rapid test. Patients with non-reactive versus reactive tests had a significantly shorter median time since infection (p=0.01), time since onset of symptoms (p=0.009), higher proportion with Fiebig stage III versus IV (p=0.003), negative WB results (p=0.007), higher HIV-RNA levels (p=0.001) and lower CD4+ and CD8+ cell count (p=0.03, p<0.001, respectively). When examining sensitivity over the course of AHI duration, the probability of HIV detection was 75.5% at 5 weeks from HIV transmission. The INSTI provided similar results with respect to proportion of reactive tests (62.5%), determinants for non-reactive test and probability of HIV detection at 5 weeks of infection (85.0%).ConclusionsOver half of AHI patients had reactive serology using the STAT-VIEW rapid self-test when performed on serum samples. Considering that detection sensitivity increased substantially over infection time, individuals should not rely on a negative result to accurately exclude HIV infection within at least 5 weeks of potential HIV exposure. Notwithstanding strong recommendations against rapid test use during AHI, some utility in detecting HIV is observed 5–12 weeks after transmission.

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A Rapid Immunochromatographic Method Based on a Secondary Antibody-Labelled Magnetic Nanoprobe for the Detection of Hepatitis B preS2 Surface Antigen

Biosensors ◽

10.3390/bios10110161 ◽

2020 ◽

Vol 10 (11) ◽

pp. 161

Author(s):

Yangyang Cai ◽

Jun Yan ◽

Li Zhu ◽

Hengliang Wang ◽

Ying Lu

Keyword(s):

Hepatitis B ◽

Large Scale ◽

Limit Of Detection ◽

Point Of Care ◽

Secondary Antibody ◽

Serum Samples ◽

Standard Curve ◽

Signal Characteristics ◽

Viral Infectious Disease ◽

The Stability

Hepatitis B is a globally prevalent viral infectious disease caused by the hepatitis B virus (HBV). In this study, an immunochromatographic assay (ICA) for the rapid detection of hepatitis B preS2 antigen (preS2Ag) was established. The magnetic nanoparticles (MNPs) indirectly labelled with goat anti-mouse (GAM) secondary antibody were applied as a nanoprobe for free preS2 antibody (preS2Ab) capturing and signal amplification. By employing sample pre-incubation processing as well, preS2Ag-preS2Ab was sufficiently caught by the GAM-MNPs probe in 5 min. A qualitative sensitivity of 625 ng/mL was obtained by naked-eye observation within 15–20 min. A standard curve (0–5000 ng/mL) was established, with a quantitative limit of detection (LOD) of 3.6 ng/mL, based on the stability and penetrability of the magnetic signal characteristics. The proposed method for preS2Ag was rapid (~25 min, cf. ELISA ~4 h) and had a good accuracy, which was verified using an ELISA kit (relative error < 15%). Large equipment and skilled technicians were not required. The sensitivity and specificity of the developed GAM-MNPs-ICA method were 93.3% and 90% in clinical serum samples (n = 25), respectively. A good detection consistency (84%) was observed between the developed ICA method and 2 types of commercial ELISA kits, indicating that the GAM-MNPs-ICA has a potential application in large-scale screening for and point-of-care diagnosis of hepatitis B or other infectious diseases.

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