scholarly journals Highly Multiplexed Label-Free Imaging Sensor for Accurate Quantification of Small-Molecule Binding Kinetics

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 37
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
Fulya Ekiz Kanik ◽  
John Rejman ◽  
...  
Keyword(s):  
Small Molecule ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Fumonisin B1 ◽  
Biomass Accumulation ◽  
Binding Kinetics ◽  
Label Free ◽  
Common Path ◽  
Label Free Detection ◽  
Imaging Sensor

Investigating the binding kinetics of small molecule analytes to larger ligands, such as proteins and antibodies, is a compelling task for the field of drug and biomarker development, as well as the food industry and agro-biotechnology. Here, we improve the limit of detection of the Interferometric Reflectance Imaging Sensor (IRIS), a label-free, highly multiplexed biosensor, to perform real-time affinity measurement of small molecules binding to immobilized antibodies in a microarray format. As the analytes bind to the surface probes, the biomass accumulation on the surface is quantified by measuring the optical reflectance from the layered Si/SiO2 chip through the solution, in a common-path interferometer configuration. As a proof of concept, label-free detection of biotin molecules binding to immobilized streptavidin probes is performed, achieving 1 pg/mm2 sensitivity through signal averaging in a shot noise limited operation. Furthermore, we apply the optimized sensor to the screening of a 20-multiplexed antibody chip (MW~150 kDa ligands) against Fumonisin B1 (MW = 721.8 Da), one of the most prevalent mycotoxins found in many cereal grains such as corn and wheat. The simultaneously recorded binding curves of the toxin to the multiplexed sensor yield a signal-to-noise ratio of ≈8 when noise reduction methods of spatial and temporal averaging are utilized.

scholarly journals Highly Multiplexed Label-Free Imaging Sensor for Accurate Quantification of Small-Molecule Binding Kinetics

ACS Omega ◽  
2020 ◽  
Vol 5 (39) ◽  
pp. 25358-25364
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
Fulya Ekiz Kanik ◽  
John Rejman ◽  
...  
Keyword(s):  
Small Molecule ◽  
Binding Kinetics ◽  
Label Free ◽  
Imaging Sensor ◽  
Accurate Quantification

scholarly journals Surface Plasmon Resonance Assay for Label-Free and Selective Detection of HIV-1 p24 Protein

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 180
Author(s):  
Lucia Sarcina ◽  
Giuseppe Felice Mangiatordi ◽  
Fabrizio Torricelli ◽  
Paolo Bollella ◽  
Zahra Gounani ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Covalent Binding ◽  
Hiv Infections ◽  
Selectivity Ratio ◽  
Selective Detection ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Label Free Detection ◽  
P24 Protein ◽  
Hiv 1

The early detection of the human immunodeficiency virus (HIV) is of paramount importance to achieve efficient therapeutic treatment and limit the disease spreading. In this perspective, the assessment of biosensing assay for the HIV-1 p24 capsid protein plays a pivotal role in the timely and selective detection of HIV infections. In this study, multi-parameter-SPR has been used to develop a reliable and label-free detection method for HIV-1 p24 protein. Remarkably, both physical and chemical immobilization of mouse monoclonal antibodies against HIV-1 p24 on the SPR gold detecting surface have been characterized for the first time. The two immobilization techniques returned a capturing antibody surface coverage as high as (7.5 ± 0.3) × 1011 molecule/cm2 and (2.4 ± 0.6) × 1011 molecule/cm2, respectively. However, the covalent binding of the capturing antibodies through a mixed self-assembled monolayer (SAM) of alkanethiols led to a doubling of the p24 binding signal. Moreover, from the modeling of the dose-response curve, an equilibrium dissociation constant KD of 5.30 × 10−9 M was computed for the assay performed on the SAM modified surface compared to a much larger KD of 7.46 × 10−5 M extracted for the physisorbed antibodies. The chemically modified system was also characterized in terms of sensitivity and selectivity, reaching a limit of detection of (4.1 ± 0.5) nM and an unprecedented selectivity ratio of 0.02.

Label-free detection of small-molecule binding to a GPCR in the membrane environment

2015 ◽  
Vol 1854 (8) ◽  
pp. 979-986 ◽  
Author(s):  
Roland G. Heym ◽  
Wilfried B. Hornberger ◽  
Viktor Lakics ◽  
Georg C. Terstappen
Keyword(s):  
Small Molecule ◽  
Label Free ◽  
Label Free Detection

One-Dimensional Diffraction Grating of Poly(Methacrylic Acid) Brushes For The Rapid Label-Free Detection of Yersinia Pestis With a Reflective Laser System

2021 ◽  
Author(s):  
Feng-Ping Lin ◽  
Hui-Ling Hsu ◽  
Hui-Chung Lin ◽  
Hsin-Hsien Huang ◽  
Chien-Hsing Lu ◽  
...  
Keyword(s):  
Laser Beam ◽  
Yersinia Pestis ◽  
Methacrylic Acid ◽  
Limit Of Detection ◽  
Incident Angle ◽  
Diffraction Effect ◽  
Label Free ◽  
Diffraction Intensity ◽  
One Dimensional ◽  
Label Free Detection

Abstract Background: Because of the low sensitivity of commercial products, development of a facile method to rapidly identify plague on-site remains highly attractive. Line arrays of poly(methacrylic acid) (PMAA) brushes were grafted using a photoresist template to fabricate one-dimensional diffraction gratings (DGs). The as-prepared samples first bound protein G to immobilize and orient the tails of the antibody of Yersinia pestis (abY). A laser beam was employed to analyze the 2D and 3D reflective signals of DGs at an incident angle of 45°. The abY-tailed PMAA DG possessed an optical feature with a characteristic diffraction effect along the SII, in which the projection of the laser beam on the plane of the DG chip was parallel to the strips, and ST configurations, in which they were perpendicular. A fluidic diffraction chip based on the abY-tailed PMMA DG was fabricated to examine the ability to detect Yersinia pestis along the ST configuration. Results: Upon flowing through the chip, Yersinia pestis was attached to the abY-tailed PMMA DG, which changed the diffraction intensity. The degree of the diffraction intensity exhibited a linear response to Yersinia pestis at concentrations from 102 to 107 CFU mL−1, and the limit of detection was 75 CFU mL−1, 1000 times lower than a commercial product (Alexter Bio-Detect Test). The diffractive sensor could selectively detect Yersinia pestis in spiked serum samples, with excellent standard deviation and recovery. Conclusion: Our platform provides a simple, label-free method for on-site plague diagnosis to prevent the highly rapid transmission of plague.

scholarly journals A Simple Displacement Aptamer Assay on Resistive Pulse Sensor for Small Molecule Detection

2020 ◽  
Author(s):  
Rhushabh Maugi ◽  
bernadette gamble ◽  
david bunka ◽  
Mark Platt
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Label Free ◽  
Resistive Pulse ◽  
Pulse Sensor ◽  
Label Free Detection ◽  
Ssdna Aptamer ◽  
Aptamer Assay ◽  
Small Molecule Detection ◽  
Surface Changes

A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing for the rapid and label free detection of small molecules. The surface of a magnetic nanocarrier was first modified with a ssDNA aka linker which is designed to be partially complimentary in sequence to a ssDNA aptamer. The aptamer and linker form a stable dsDNA complex on the nanocarriers surface. Upon the addition of the target molecule, a conformational change takes place where the aptamer preferentially binds to the target over the linker; causing the aptamer to be released into solution. The RPS measures the change in velocity of the nanocarrier as its surface changes from dsDNA to ssDNA, and its velocity is used as a proxy for the concentration of the target. We illustrate the versatility of the assay by demonstrating the detection of the antibiotic Moxifloxacin, and chemotherapeutics Imatinib and Irinotecan.

scholarly journals Rapid label-free SERS detection of foodborne pathogenic bacteria based on hafnium ditelluride-Au nanocomposites

2020 ◽  
Vol 13 (05) ◽  
pp. 2041004 ◽  
Author(s):  
Yang Li ◽  
Yanxian Guo ◽  
Binggang Ye ◽  
Zhengfei Zhuang ◽  
Peilin Lan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Limit Of Detection ◽  
Principal Component ◽  
High Sensitivity ◽  
Chemical Mechanism ◽  
Sers Substrate ◽  
Label Free ◽  
Label Free Detection ◽  
Surface Enhanced Raman ◽  
Foodborne Pathogenic Bacteria

Two-dimensional (2D) nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features. Herein, 2D hafnium ditelluride (HfTe[Formula: see text], a new member of transition metal tellurides, is exploited to support gold nanoparticles fabricating HfTe2-Au nanocomposites. The nanohybrids can serve as novel 2D surface-enhanced Raman scattering (SERS) substrate for the label-free detection of analyte with high sensitivity and reproducibility. Chemical mechanism originated from HfTe2 nanosheets and the electromagnetic enhancement induced by the hot spots on the nanohybrids may largely contribute to the superior SERS effect of HfTe2-Au nanocomposites. Finally, HfTe2-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bacteria, which realize the rapid and ultrasensitive Raman test of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to [Formula: see text]. Combined with principal component analysis, HfTe2-Au-based SERS analysis also completes the bacterial classification without extra treatment.

scholarly journals An aptameric graphene nanosensor for label-free detection of small-molecule biomarkers

2015 ◽  
Vol 71 ◽  
pp. 222-229 ◽  
Author(s):  
Cheng Wang ◽  
Jinho Kim ◽  
Yibo Zhu ◽  
Jaeyoung Yang ◽  
Gwan-Hyoung Lee ◽  
...  
Keyword(s):  
Small Molecule ◽  
Label Free ◽  
Label Free Detection

scholarly journals Plasmonic nanocrystals on polycarbonate substrates for direct and label-free biodetection of Interleukin-6 in bioengineered 3D skeletal muscles

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerardo A Lopez-Muñoz ◽  
Juan M Fernández-Costa ◽  
Maria Alejandra Ortega ◽  
Jordina Balaguer-Trias ◽  
Eduard Martin-Lasierra ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Culture Media ◽  
Incident Angle ◽  
Wide Field ◽  
Label Free ◽  
Cell Culture Media ◽  
Muscle Tissues ◽  
Label Free Detection ◽  
Potential Benefits

Abstract The development of nanostructured plasmonic biosensors has been widely widespread in the last years, motivated by the potential benefits they can offer in integration, miniaturization, multiplexing opportunities, and enhanced performance label-free biodetection in a wide field of applications. Between them, engineering tissues represent a novel, challenging, and prolific application field for nanostructured plasmonic biosensors considering the previously described benefits and the low levels of secreted biomarkers (≈pM–nM) to detect. Here, we present an integrated plasmonic nanocrystals-based biosensor using high throughput nanostructured polycarbonate substrates. Metallic film thickness and incident angle of light for reflectance measurements were optimized to enhance the detection of antibody–antigen biorecognition events using numerical simulations. We achieved an enhancement in biodetection up to 3× as the incident angle of light decreases, which can be related to shorter evanescent decay lengths. We achieved a high reproducibility between channels with a coefficient of variation below 2% in bulk refractive index measurements, demonstrating a high potential for multiplexed sensing. Finally, biosensing potential was demonstrated by the direct and label-free detection of interleukin-6 biomarker in undiluted cell culture media supernatants from bioengineered 3D skeletal muscle tissues stimulated with different concentrations of endotoxins achieving a limit of detection (LOD) of ≈ 0.03 ng/mL (1.4 pM).

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