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

Author(s):  
Rhushabh Maugi ◽  
bernadette gamble ◽  
david bunka ◽  
Mark Platt

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.

2020 ◽  
Author(s):  
Rhushabh Maugi ◽  
bernadette gamble ◽  
david bunka ◽  
Mark Platt

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.


Talanta ◽  
2020 ◽  
pp. 122068
Author(s):  
Rushabh. Maugi ◽  
Bernadette. Gamble ◽  
David Bunka ◽  
Mark Platt

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4126 ◽  
Author(s):  
Riikka Peltomaa ◽  
Bettina Glahn-Martínez ◽  
Elena Benito-Peña ◽  
María Moreno-Bondi

Label-free optical biosensors are an intriguing option for the analyses of many analytes, as they offer several advantages such as high sensitivity, direct and real-time measurement in addition to multiplexing capabilities. However, development of label-free optical biosensors for small molecules can be challenging as most of them are not naturally chromogenic or fluorescent, and in some cases, the sensor response is related to the size of the analyte. To overcome some of the limitations associated with the analysis of biologically, pharmacologically, or environmentally relevant compounds of low molecular weight, recent advances in the field have improved the detection of these analytes using outstanding methodology, instrumentation, recognition elements, or immobilization strategies. In this review, we aim to introduce some of the latest developments in the field of label-free optical biosensors with the focus on applications with novel innovations to overcome the challenges related to small molecule detection. Optical label-free methods with different transduction schemes, including evanescent wave and optical fiber sensors, surface plasmon resonance, surface-enhanced Raman spectroscopy, and interferometry, using various biorecognition elements, such as antibodies, aptamers, enzymes, and bioinspired molecularly imprinted polymers, are reviewed.


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

2020 ◽  
Vol 12 (21) ◽  
pp. 2674-2681
Author(s):  
Fatemeh Shafiei ◽  
Kathleen McAuliffe ◽  
Yousef Bagheri ◽  
Zhining Sun ◽  
Qikun Yu ◽  
...  

A paper-based portable fluorogenic RNA sensor for the selective, sensitive, and rapid detection of target analytes.


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

2015 ◽  
Author(s):  
Xiangying Guan ◽  
Alok Upadhyay ◽  
Sudipto Munshi ◽  
Raj Chakrabarti

AbstractSirtuin enzymes are NAD+-dependent protein deacylases that play a central role in the regulation of healthspan and lifespan in organisms ranging from yeast to mammals. There is intense interest in the activation of the seven mammalian sirtuins (SIRT1-7) in order to extend mammalian healthspan and lifespan. However, there is currently no understanding of how to design sirtuin-activating compounds beyond allosteric activators of SIRT1-catalyzed reactions that are limited to particular substrates. Moreover, across all families of enzymes, only a dozen or so distinct classes of non-natural small molecule activators have been characterized, with only four known modes of activation among them. None of these modes of activation are based on the unique catalytic reaction mechanisms of the target enzymes. Here, we report a general mode of sirtuin activation that is distinct from the known modes of enzyme activation. Based on the conserved mechanism of sirtuin-catalyzed deacylation reactions, we establish biophysical properties of small molecule modulators that can in principle result in enzyme activation for diverse sirtuins and substrates. Building upon this framework, we propose strategies for the identification, characterization and evolution of hits for mechanism-based enzyme activating compounds. We characterize several small molecules reported in the literature to activate sirtuins besides SIRT1, using a variety of biochemical and biophysical techniques including label-free and labeled kinetic and thermodynamic assays with multiple substrates and protocols for the identification of false positives. We provide evidence indicating that several of these small molecules reported in the published literature are false positives, and identify others as hit compounds for the design of compounds that can activate sirtuins through the proposed mechanism-based mode of action.


Sign in / Sign up

Export Citation Format

Share Document