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 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 Critical angle reflection imaging for quantification of molecular interactions on glass surface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guangzhong Ma ◽  
Runli Liang ◽  
Zijian Wan ◽  
Shaopeng Wang
Keyword(s):  
Refractive Index ◽  
Small Molecule ◽  
Molecular Interactions ◽  
Glass Surface ◽  
Critical Angle ◽  
Dynamic Range ◽  
Refractive Index Change ◽  
Label Free ◽  
Index Change ◽  
Sensing Range

AbstractQuantification of molecular interactions on a surface is typically achieved via label-free techniques such as surface plasmon resonance (SPR). The sensitivity of SPR originates from the characteristic that the SPR angle is sensitive to the surface refractive index change. Analogously, in another interfacial optical phenomenon, total internal reflection, the critical angle is also refractive index dependent. Therefore, surface refractive index change can also be quantified by measuring the reflectivity near the critical angle. Based on this concept, we develop a method called critical angle reflection (CAR) imaging to quantify molecular interactions on glass surface. CAR imaging can be performed on SPR imaging setups. Through a side-by-side comparison, we show that CAR is capable of most molecular interaction measurements that SPR performs, including proteins, nucleic acids and cell-based detections. In addition, we show that CAR can detect small molecule bindings and intracellular signals beyond SPR sensing range. CAR exhibits several distinct characteristics, including tunable sensitivity and dynamic range, deeper vertical sensing range, fluorescence compatibility, broader wavelength and polarization of light selection, and glass surface chemistry. We anticipate CAR can expand SPR′s capability in small molecule detection, whole cell-based detection, simultaneous fluorescence imaging, and broader conjugation chemistry.

scholarly journals A Reliable, Label Free Quality Control Method for the Production of DNA Microarrays with Clinical Applications

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 340
Author(s):  
Elisa Chiodi ◽  
Francesco Damin ◽  
Laura Sola ◽  
Lucia Ferraro ◽  
Dario Brambilla ◽  
...  
Keyword(s):  
Quality Control ◽  
Dna Microarrays ◽  
Control Method ◽  
False Negative ◽  
Label Free ◽  
Negative Results ◽  
System A ◽  
Quality Control Method ◽  
False Negative Results ◽  
Imaging Sensor

The manufacture of a very high-quality microarray support is essential for the adoption of this assay format in clinical routine. In fact, poorly surface-bound probes can affect the diagnostic sensitivity or, in worst cases, lead to false negative results. Here we report on a reliable and easy quality control method for the evaluation of spotted probe properties in a microarray test, based on the Interferometric Reflectance Imaging Sensor (IRIS) system, a high-resolution label free technique able to evaluate the variation of the mass bound to a surface. In particular, we demonstrated that the IRIS analysis of microarray chips immediately after probe immobilization can detect the absence of probes, which recognizably causes a lack of signal when performing a test, with clinical relevance, using fluorescence detection. Moreover, the use of the IRIS technique allowed also to determine the optimal concentration of the probe, that has to be immobilized on the surface, to maximize the target recognition, thus the signal, but to avoid crowding effects. Finally, through this preliminary quality inspection it is possible to highlight differences in the immobilization chemistries. In particular, we have compared NHS ester versus click chemistry reactions using two different surface coatings, demonstrating that, in the diagnostic case used as an example (colorectal cancer) a higher probe density does not reflect a higher binding signal, probably because of a crowding effect.

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

scholarly journals Label-free electrochemical biosensing of small-molecule inhibition on O-GlcNAc glycosylation

2017 ◽  
Vol 95 ◽  
pp. 94-99 ◽  
Author(s):  
Yu Yang ◽  
Yuxin Gu ◽  
Bin Wan ◽  
Xiaomin Ren ◽  
Liang-Hong Guo
Keyword(s):  
Small Molecule ◽  
Label Free ◽  
Small Molecule Inhibition ◽  
Electrochemical Biosensing

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.

Back to Basics: Label-Free Technologies for Small Molecule Screening

2008 ◽  
Vol 11 (3) ◽  
pp. 231-237 ◽  
Author(s):  
Andrew Shiau ◽  
Mark Massari ◽  
Can Ozbal
Keyword(s):  
Small Molecule ◽  
Label Free ◽  
Small Molecule Screening

Construction of a Universal and Label-Free Chemiluminescent Sensor for Accurate Quantification of Both Bacteria and Human Methyltransferases

2020 ◽  
Vol 92 (19) ◽  
pp. 13573-13580 ◽  
Author(s):  
Zi-yue Wang ◽  
Peng Li ◽  
Lin Cui ◽  
Qinfeng Xu ◽  
Chun-yang Zhang
Keyword(s):  
Label Free ◽  
Accurate Quantification

A Label-Free Untethered Approach to Single-Molecule Protein Binding Kinetics

Nano Letters ◽  
2014 ◽  
Vol 14 (10) ◽  
pp. 5787-5791 ◽  
Author(s):  
Ahmed A. Al Balushi ◽  
Reuven Gordon
Keyword(s):  
Protein Binding ◽  
Single Molecule ◽  
Binding Kinetics ◽  
Label Free ◽  
Protein Binding Kinetics
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