Engineering an Au Nanostar-based Liquid Phase Interfacial Ratiometric SERS platform with Programmable Entropy-driven DNA Circuits to Detect Protein biomarkers in clinical samples

2021 ◽  
Author(s):  
Guanli Fan ◽  
Xiaorong Gao ◽  
Shuling Xu ◽  
Qi Zhanf ◽  
Xia Li ◽  
...  

Developing sensing platforms that simultaneously integrate high sensitivity and accuracy has been a promising but challenging task for protein biomarkers in clinical samples. Herein, we engineered an Au nanostar-based liquid...

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1876
Author(s):  
Daneish Despot ◽  
Micaela Pacheco Fernández ◽  
Matthias Barjenbruch

Hydrogen sulfide (H2S) related to wastewater in sewer systems is known for causing significant problems of corrosion and odor nuisance. Sewer systems severely affected by H2S typically rely on online H2S gas sensors for monitoring and control. However, these H2S gas sensors only provide information about the H2S emission potential at the point being monitored, which is sometimes inadequate to design control measures. In this study, a comparison of three market-ready online sensors capable of liquid-phase H2S detection in sewer systems was assessed and compared. Two of the three sensors are based on UV/Vis spectrophotometry, while the other adapted the design and principles of a Clark-type electrochemical microsensor. The H2S measurements of the sensors were statistically compared to a standard laboratory method at first. Following that, the performance of the online sensors was evaluated under realistic sewer conditions using the Berlin Water Company (BWB) research sewer pilot plant. Test applications representing scenarios of typical H2S concentrations found in sulfide-affected sewers and during control measures were simulated. The UV/Vis spectrometers showed that the performance of the sensors was highly dependent on the calibration type and measurements used for deriving the calibration function. The electrochemical sensor showed high sensitivity by responding to alternating anaerobic/anoxic conditions simulated during nitrate dosing. All sensors were prone to measurement disturbances due to high amounts of sanitary solids in wastewater at the study site and required continuous maintenance for reliable measurements. Finally, a summary of the key attributes and limitations of the sensors compared for liquid phase H2S detection is outlined.


2007 ◽  
Vol 2 ◽  
pp. 117727190700200 ◽  
Author(s):  
Ziad J. Sahab ◽  
Suzan M. Semaan ◽  
Qing-Xiang Amy Sang

Biomarkers are biomolecules that serve as indicators of biological and pathological processes, or physiological and pharmacological responses to a drug treatment. Because of the high abundance of albumin and heterogeneity of plasma lipoproteins and glycoproteins, biomarkers are difficult to identify in human serum. Due to the clinical significance the identification of disease biomarkers in serum holds great promise for personalized medicine, especially for disease diagnosis and prognosis. This review summarizes some common and emerging proteomics techniques utilized in the separation of serum samples and identification of disease signatures. The practical application of each protein separation or identification technique is analyzed using specific examples. Biomarkers of cancers of prostate, breast, ovary, and lung in human serum have been reviewed, as well as those of heart disease, arthritis, asthma, and cystic fibrosis. Despite the advancement of technology few biomarkers have been approved by the Food and Drug Administration for disease diagnosis and prognosis due to the complexity of structure and function of protein biomarkers and lack of high sensitivity, specificity, and reproducibility for those putative biomarkers. The combination of different types of technologies and statistical analysis may provide more effective methods to identify and validate new disease biomarkers in blood.


2021 ◽  
Vol 8 ◽  
Author(s):  
Alfredo Garcia-Venzor ◽  
Bertha Rueda-Zarazua ◽  
Eduardo Marquez-Garcia ◽  
Vilma Maldonado ◽  
Angelica Moncada-Morales ◽  
...  

As to date, more than 49 million confirmed cases of Coronavirus Disease 19 (COVID-19) have been reported worldwide. Current diagnostic protocols use qRT-PCR for viral RNA detection, which is expensive and requires sophisticated equipment, trained personnel and previous RNA extraction. For this reason, we need a faster, direct and more versatile detection method for better epidemiological management of the COVID-19 outbreak. In this work, we propose a direct method without RNA extraction, based on the Loop-mediated isothermal amplification (LAMP) and Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein (CRISPR-Cas12) technique that allows the fast detection of SARS-CoV-2 from patient samples with high sensitivity and specificity. We obtained a limit of detection of 16 copies/μL with high specificity and at an affordable cost. The diagnostic test readout can be done with a real-time PCR thermocycler or with the naked eye in a blue-light transilluminator. Our method has been evaluated on a small set of clinical samples with promising results.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9507
Author(s):  
Dandan Li ◽  
Jie Wu ◽  
Zhongjuan Liu ◽  
Ling Qiu ◽  
Yimin Zhang

Background Distinguishing between different types of thyroid cancers (TC) remains challenging in clinical laboratories. As different tumor types require different clinical interventions, it is necessary to establish new methods for accurate diagnosis of TC. Methods Proteomic analysis of the human serum was performed through data-independent acquisition mass spectrometry for 29 patients with TC (stages I–IV): 13 cases of papillary TC (PTC), 10 cases of medullary TC (MTC), and six cases follicular TC (FTC). In addition, 15 patients with benign thyroid nodules (TNs) and 10 healthy controls (HCs) were included in this study. Subsequently, 17 differentially expressed proteins were identified in 291 patients with TC, including 247 with PTC, 38 with MTC, and six with FTC, and 69 patients with benign TNs and 176 with HC, using enzyme-linked immunosorbent assays. Results In total, 517 proteins were detected in the serum samples using an Orbitrap Q-Exactive-plus mass spectrometer. The amyloid beta A4 protein, apolipoprotein A-IV, gelsolin, contactin-1, gamma-glutamyl hydrolase, and complement factor H-related protein 1 (CFHR1) were selected for further analysis. The median serum CFHR1 levels were significantly higher in the MTC and FTC groups than in the PTC and control groups (P < 0.001). CFHR1 exhibited higher diagnostic performance in distinguishing patients with MTC from those with PTC (P < 0.001), with a sensitivity of 100.0%, specificity of 85.08%, area under the curve of 0.93, and detection cut-off of 0.92 ng/mL. Conclusion CFHR1 may serve as a novel biomarker to distinguish PTC from MTC with high sensitivity and specificity.


Author(s):  
E. Gazzola ◽  
A. Pozzato ◽  
G. Ruffato ◽  
E. Sovernigo ◽  
A. Sonato

AbstractSurface plasmon resonance biosensors have recently known a rapid diffusion in the biological field and a large variety of sensor configurations is currently available. Biological applications are increasingly demanding sensor miniaturization, multiple detection in parallel, temperature-controlled environment and high sensitivity. Indeed, versatile and tunable sensing platforms, together with an accurate biological environment monitoring, could improve the realization of custom biosensing devices applicable to different biological reactions. Here we propose a smart and high throughput fabrication protocol for the realization of a custommicrofluidic plasmonic biochip that could be easily tuned and modified to address different biological applications. The sensor chip here presented shows a high sensing capability, monitored by an accurate signal calibration in the presence of concentration and temperature variation.


2021 ◽  
Author(s):  
Aysevil Salman Durmuşlar ◽  
Emine Ates ◽  
Ahmet Biçer ◽  
Sualp Deniz ◽  
Ahmet Cicek ◽  
...  

Abstract A practical and portable ultrasonic interferometric sensor to detect methanol concentration in ethanol in the liquid phase is numerically investigated. For high-sensitivity operation, the sensor is designed as a Mach-Zehnder interferometer based on a linear-defect waveguide in a two-dimensional phononic crystal, which consists of square array of cylindrical steel rods in water. The waveguide core comprises polyethylene tubing, impedance-matched with water, filled with either pure ethanol or ethanol-methanol binary mixture, allowing fast replacement of the analyte. Band structure analyses through the finite-element method are carried out to obtain guiding modes at frequencies around 200 kHz. With 50x21 cells with 4.2 mm periodicity, the total sensor area is 210-by-88.2 millimeters, which can be significantly reduced by increasing the operating frequency to megahertz range. The interferometer is constructed via T junctions of the waveguide, which facilitates low-loss equal splitting and recollection of ultrasonic waves. Sample and reference wave paths are constructed by filling polyethylene tubing on the upper and lower halves of the interferometer with the ethanol-methanol mixture and pure ethanol, respectively. Frequency-domain finite-element method simulations reveal that the sensor output is characterized by several transmission peaks, one of which is centered at 203.35 kHz with a full-width at half-maximum of 20 Hz, resulting in a quality factor of 10167. The peak frequency of this peak redshifts at a rate of 7.24 Hz per percent volume fraction change in methanol. The peak shift is linear when the methanol volume fraction is below 10%. Besides, the interferometric sensor has a figure of merit around 0.35. The proposed ultrasonic sensor offers rapid detection of methanol content in ethanol with high sensitivity.


Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 827
Author(s):  
Paula Rodrigues de Almeida ◽  
Ana Karolina Antunes Eisen ◽  
Meriane Demoliner ◽  
Fernando Rosado Spilki

Zika virus (ZIKV) is an important arbovirus, responsible for recent outbreaks of Guillain Barré Syndrome and Congenital Zika Syndrome (CZS). After thousands of CZS cases, ZIKV is under constant surveillance in Brazil. Reliable and robust detection techniques are required to minimize the influence of host inhibitors from clinical samples and mosquito pool samples. Reverse transcription Digital Polymerase Chain Reaction (RT-dPCR) is a technique that allows the accurate quantification of DNA targets with high sensitivity, and it is usually less affected by inhibitors than RT-qPCR. This study aimed to assess the influence of mosquito tissue, RNA extraction and cDNA synthesis in ZIKV PCR detection. Samples containing 0, 3 and 10 mosquitoes were spiked with ZIKV MR766 and serially diluted prior to RNA extraction and RT-dPCR for ZIKV. Two reverse transcription protocols were tested. Assay sensitivity allowed the detection of 1.197 copies/µL. A higher correlation between dilution factor and target quantification was observed in 10 mosquito pool samples. The lower quantification in samples diluted without mosquitoes highlights the critical role of the reverse transcription step in RNA detection, since it could be attributed to reverse transcriptase variable performance in samples with low overall RNA concentration. The results in mosquito pools indicate that mosquito tissues do not inhibit ZIKV RT-dPCR, and the RT-dPCR technique has good sensitivity and robustness for ZIKV detection in mosquito pool samples regardless of mosquito tissue concentration.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1003 ◽  
Author(s):  
Jin-Ha Choi ◽  
Jin-Ho Lee ◽  
Joohyung Son ◽  
Jeong-Woo Choi

For the early diagnosis of several diseases, various biomarkers have been discovered and utilized through the measurement of concentrations in body fluids such as blood, urine, and saliva. The most representative analytical method for biomarker detection is an immunosensor, which exploits the specific antigen-antibody immunoreaction. Among diverse analytical methods, surface plasmon resonance (SPR)-based immunosensors are emerging as a potential detection platform due to high sensitivity, selectivity, and intuitive features. Particularly, SPR-based immunosensors could detect biomarkers without labeling of a specific detection probe, as typical immunosensors such as enzyme-linked immunosorbent assay (ELISA) use enzymes like horseradish peroxidase (HRP). In this review, SPR-based immunosensors utilizing noble metals such as Au and Ag as SPR-inducing factors for the measurement of different types of protein biomarkers, including viruses, microbes, and extracellular vesicles (EV), are briefly introduced.


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