Towards an Integrated System as Point-of-Care Device for the Optical Detection of Sepsis Biomarkers

Severe infection and sepsis are a common, expensive, and frequently fatal conditions in critically ill patients. The sepsis diagnosis is not trivial, since it is an extremely complex chain of events involving inflammatory and anti-inflammatory processes, cellular reactions, and circulatory disorders. For these reasons, delay in diagnosis and initiation of drug treatments have shown to be crucial for this pathology. Moreover, a multitude of biomarkers has been proposed, many more than for other pathologies. In order to select optimal treatments for the highly heterogeneous group of sepsis patients and to reduce costs, novel multiplexed tools that better characterize the patient and his or her specific immune response are highly desired. In order to achieve the fundament of drastically improved multi-analyte detection and to attain low limits of detection in diagnostics, the area of point-of-care testing (POCT) technology is developing quickly, leading to the production of instruments, the reliability of which is continuously increasing. For this purpose, a selection of two biomarkers—C-reactive protein (CRP) and neopterin (NP)—was studied in this paper and a fluorescence-based integrated optical system, suitable for future POCT applications, was implemented that is capable of performing the simultaneous measurement of the two different biomarkers in replicate. A limit of detection of 10 and 2.1 µg L−1 was achieved for CRP and NP spiked in commercially available human serum, respectively. Moreover, measurements on both biomarkers were also performed on serum samples collected from septic patients.

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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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Demonstration of a Label-Free and Low-Cost Optical Cavity-Based Biosensor Using Streptavidin and C-Reactive Protein

Biosensors ◽

10.3390/bios11010004 ◽

2020 ◽

Vol 11 (1) ◽

pp. 4

Author(s):

Donggee Rho ◽

Seunghyun Kim

Keyword(s):

Limit Of Detection ◽

Point Of Care ◽

Low Cost ◽

Optical Cavity ◽

Sample Volume ◽

Small Sample ◽

Label Free ◽

C Reactive Protein ◽

Reactive Protein ◽

Cavity Structure

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.

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Wave-shaped microfluidic chip assisted point-of-care testing for accurate and rapid diagnosis of infections

10.21203/rs.3.rs-829274/v1 ◽

2021 ◽

Author(s):

Binfeng Yin ◽

Xinhua Wan ◽

Mingzhu Yang ◽

Changcheng Qian ◽

A S M Muhtasim Fuad Sohan

Keyword(s):

Microfluidic Chip ◽

Limit Of Detection ◽

Point Of Care ◽

Simultaneous Detection ◽

Accurate Diagnosis ◽

Point Of Care Testing ◽

Promising Alternative ◽

Reactive Protein ◽

Linear Relationships ◽

Multiple Biomarkers

Abstract Background: Simultaneous and timely detection of C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) provides effective information for the accurate diagnosis of infections. Early diagnosis and classification of infections increase the cure rate while decreasing complications, which is significant for severe infections, especially for war surgery. However, traditional methods rely on laborious operations and bulky devices. On the other hand, point-of-care (POC) methods suffer from limited robustness and accuracy. Therefore, it is of urgent demand to develop POC devices for rapid and accurate diagnosis of infections to fulfill on-site militarized requirements.Methods: We developed a wave-shaped microfluidic chip (WMC) assisted multiplexed detection platform (WMC-MDP). WMC-MDP reduces detection time and improves repeatability through premixing of the samples and reaction of the reagents. We further combined the detection platform with the streptavidin-biotin (SA-B) amplified system to enhance the sensitivity while using chemiluminescence (CL) intensity as signal readout. We realized simultaneous detection of CRP, PCT, and IL-6 on the detection platform and evaluated the sensitivity, linear range, selectivity, and repeatability. Finally, we finished detecting 15 samples from volunteers and compared the results with commercial ELISA kits.Results: Detection of CRP, PCT, and IL-6 exhibited good linear relationships between CL intensities and concentrations in the range of 1.25-40 μg/mL, 0.4-12.8 ng/mL, and 50-1600 pg/mL. The limit of detection (LOD) of CRP, PCT, and IL-6 were 0.54 μg/mL, 0.11 ng/mL, and 16.25 pg/mL, respectively. WMC-MDP is capable of good adequate selectivity and repeatability. The whole detection procedure takes only 22 minutes that meets the requirements of a POC device. Results of 15 samples from volunteers were consistent with the results detected by commercial ELISA kits.Conclusion: WMC-MDP allows simultaneous, rapid, and sensitive detection of CRP, PCT, and IL-6 with satisfactory selectivity and repeatability, requiring minimal manipulation. However, WMC-MDP takes advantage of being a microfluidic device showing the coefficients of variation less than 10% enabling WMC-MDP to be a type of POCT. Therefore, WMC-MDP provides a promising alternative to point-of-care testing (POCT) of multiple biomarkers. We believe the practical application of WMC-MDP in militarized fields will revolutionize infection diagnosis for soldiers.

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Whole Blood Immunoassay Based on Centrifugal Bead Sedimentation

Clinical Chemistry ◽

10.1373/clinchem.2011.162206 ◽

2011 ◽

Vol 57 (5) ◽

pp. 753-761 ◽

Cited By ~ 44

Author(s):

Ulrich Y Schaff ◽

Greg J Sommer

Keyword(s):

Whole Blood ◽

Single Channel ◽

Limit Of Detection ◽

Point Of Care ◽

Low Cost ◽

Microfluidic System ◽

Blood Samples ◽

Reactive Protein ◽

Immunoassay Technique ◽

Microfluidic Immunoassay

BACKGROUND Centrifugal “lab on a disk” microfluidics is a promising avenue for developing portable, low-cost, automated immunoassays. However, the necessity of incorporating multiple wash steps results in complicated designs that increase the time and sample/reagent volumes needed to run assays and raises the probability of errors. We present proof of principle for a disk-based microfluidic immunoassay technique that processes blood samples without conventional wash steps. METHODS Microfluidic disks were fabricated from layers of patterned, double-sided tape and polymer sheets. Sample was mixed on-disk with assay capture beads and labeling antibodies. Following incubation, the assay beads were physically separated from the blood cells, plasma, and unbound label by centrifugation through a density medium. A signal-laden pellet formed at the periphery of the disk was analyzed to quantify concentration of the target analyte. RESULTS To demonstrate this technique, the inflammation biomarkers C-reactive protein and interleukin-6 were measured from spiked mouse plasma and human whole blood samples. On-disk processing (mixing, labeling, and separation) facilitated direct assays on 1-μL samples with a 15-min sample-to-answer time, <100 pmol/L limit of detection, and 10% CV. We also used a unique single-channel multiplexing technique based on the sedimentation rate of different size or density bead populations. CONCLUSIONS This portable microfluidic system is a promising method for rapid, inexpensive, and automated detection of multiple analytes directly from a drop of blood in a point-of-care setting.

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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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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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An origami paper-based nanoformulated immunosensor detects picograms of VEGF-C per milliliter of blood

Communications Biology ◽

10.1038/s42003-020-01607-8 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Shuai Sun ◽

Yang Wang ◽

Tao Ming ◽

Jinping Luo ◽

Yu Xing ◽

...

Keyword(s):

Limit Of Detection ◽

Point Of Care ◽

Clinical Importance ◽

High Specificity ◽

Tumor Biomarker ◽

Serum Samples ◽

Patients With Cancer ◽

Factor C ◽

Endothelial Growth Factor ◽

Walled Carbon Nanotubes

AbstractDetecting vascular endothelial growth factor C (VEGF-C), a kind of tumor biomarker, is of significant clinical importance in evaluating the prognosis of patients with cancer. However, laboratory analyses are usually not suitable for point-of-care testing because they are expensive and time consuming. In response to these challenges, we fabricated an origami paper-based microfluidic electrochemical device. To improve the specificity of VEGF-C detection, nanocomposites, synthesized by new methylene blue (NMB), amino-functional single-walled carbon nanotubes (NH2-SWCNTs), and gold nanoparticles (AuNPs), were used to modify the surface of working electrodes. Results of electrochemical detection showed that the immunosensor had excellent linearity, ranging from 0.01 to 100 ng mL−1 (R2 = 0.988), and the limit of detection was 10 pg mL−1. To confirm the high specificity of the device under real-world conditions, we evaluated the device using clinical serum samples from our hospital. The results demonstrated that the device had an excellent performance and could provide a platform for real-time detection of cancers.

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Isothermal Recombinase Polymerase Amplification-lateral Flow Detection of SARS-CoV-2, the Etiological Agent of COVID-19

10.21203/rs.3.rs-78408/v2 ◽

2020 ◽

Author(s):

Thomas R Shelite ◽

Ashanti C Uscanga-Palomeque ◽

Alejandro Castellanos ◽

Peter C Melby ◽

Bruno L Travi

Keyword(s):

Rapid Detection ◽

Limit Of Detection ◽

Point Of Care ◽

The United States ◽

Lateral Flow ◽

Recombinase Polymerase Amplification ◽

N Gene ◽

Clinical Samples ◽

Reference Test ◽

Delay In Diagnosis

Abstract The rapid detection of novel pathogens necessitates the development of easy-to-use diagnostic tests that can be readily adapted and utilized in both clinical laboratories and field settings. In December of 2019, novel coronavirus, SARS-CoV-2 (2019-nCoV), was isolated from a cluster of pneumonia patients in the Chinese city of Wuhan. The virus rapidly spread throughout the world and the first fatal cases of COVID-19 in the United States occurred in late February. The lack of testing and delay in diagnosis has facilitated the spread of this novel virus. Development of point-of-care diagnostic assays that can be performed in rural or decentralized health care centers to expand testing capacity is needed. We developed a qualitative test based on recombinase-polymerase-amplification coupled with lateral flow reading (RPA-LF) for rapid detection of SARS-CoV-2. The RPA-LF detected SARS-CoV-2 with a limit of detection of 35.4 viral nucleocapsid (N) gene copies/µL. Additionally, the RPA-LF was able to detect 0.25-2.5 copies/µL of SARS-CoV-2 N gene containing plasmid. We evaluated 37 clinical samples using CDC’s N3, N1 and N2 RT-real-time PCR assays for SARS-CoV-2 as reference test. We found a 100% concordance between RPA-LF and RT-qPCR reference test as determined by 18/18 positive and 19/19 negative samples. All positive samples had Ct values between 19-37 by RT-qPCR. The RPA-LF primers and probe did not cross react with other relevant betacoronaviruses such as SARS and MERS. This is the first isothermal amplification test paired with lateral flow developed for qualitative detection of COVID-19 allowing rapid viral detection and with prospective applicability in resource limited and decentralized laboratories.

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P216 Comparative Assessment C-reactive Protein Between a Point-of-Care Testing and Current Standard of Care (Immunonephelometric testing)

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjab076.342 ◽

2021 ◽

Vol 15 (Supplement_1) ◽

pp. S272-S273

Author(s):

G Lorenzon ◽

I Marsilio ◽

D Maniero ◽

A Rigo ◽

B Barberio ◽

...

Keyword(s):

Inflammatory Disease ◽

Point Of Care ◽

Standard Of Care ◽

Turnaround Time ◽

Blood Collection ◽

Standard Laboratory ◽

Point Of Care Testing ◽

C Reactive Protein ◽

Serum Samples ◽

Reactive Protein

Abstract Background C-reactive protein (CRP) is widely used as a biomarker of inflammatory disease activity in hospitalized and non-hospitalized patients. In particular, CRP is commonly used in patients suspected to have an inflammatory bowel disease (IBD) or with a confirmed diagnosis of IBD diagnosis in order to drive the diagnostic approach, to monitor disease activity and to guide therapeutic adjustments. However, standard laboratory CRP testing (Immunonephelometric assays) present some drawbacks, including a turnaround time of 1–2 hours, and the need of specialized equipment, offices and laboratory personnel. Because of that, point-of care testing (POCT) was recently developed in order to provide results within 2 minutes from blood collection, enabling a rapid response to clinical condition. Aim To determine the degree of analytical correlation between a recently developed POCT (ProciseDx) using capillary whole blood and the comparative Immunonephelometric assay using serum samples. Methods From October to November 2020, consecutive patients hospitalized at Gastroenterology Unit, Padua University Hospital, aged > 18 years and with clinical evidence of active inflammatory disease or infection, who underwent to a standard of care CRP test (Dimension Vista – Siemens Healthineers) were included in the study (range 2.9–340 g/L). Within 1 hour from blood collection, in each patient, CRP quantitation from capillary whole blood collected by finger stick was performed using the ProciseDx CRP assay, with reportable range between 3.6–100 g/L. A Deming regression test was used to identify the correlation between the two methods. Results Eighty-three patients were enrolled (62.5% males with mean age ± SD: 60±18). The most common indications for hospitalisation were liver disease (34.9%), pancreatic disturbance (27.7%) and suspicious or recurrence of IBD (16.7%). ProciseDx POCT with finger prick samples required a turnaround time of 2±0.2 minutes, whereas serum samples analyzed in clinical laboratory with the reference method required a turnaround time of about 180±15 minutes (p<0.001). Overall, the correlation between the two tests was high (R squared of 0.899 (95% CI 0.916–0.968)). In particular, the correlation between the methods was even higher with CRP values between 0–100 g/L with R squared of 0.961 (95% CI 0.958–0.986). Conclusion The ProciseDx POCT allows a more rapid and comparable accuracy of CRP assessment in hospitalized patients as compared to the standard laboratory measurement. Moreover, the ProciseDx POCT does not require specialised personnel to be performed. The use of ProciseDx POCT may improve and accelerate the decision-making approach, further reducing the resources required for CRP assessment.

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

NANO ◽

10.1142/s1793292018500017 ◽

2018 ◽

Vol 13 (01) ◽

pp. 1850001 ◽

Cited By ~ 5

Author(s):

Yongfeng Gao ◽

Yuanhui Feng ◽

Lu Zhou ◽

Lucia Petti ◽

Zhe Wang ◽

...

Keyword(s):

Dynamic Range ◽

Limit Of Detection ◽

Point Of Care ◽

Healthy Person ◽

Detection Sensitivity ◽

Hybrid Nanostructure ◽

Serum Samples ◽

Broad Dynamic Range ◽

Surface Enhanced Raman ◽

Relative Errors

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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