scholarly journals The Role of Surface Chemistry in the Efficacy of Protein and DNA Microarrays for Label-Free Detection: An Overview

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1026
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
M. Selim Ünlü

The importance of microarrays in diagnostics and medicine has drastically increased in the last few years. Nevertheless, the efficiency of a microarray-based assay intrinsically depends on the density and functionality of the biorecognition elements immobilized onto each sensor spot. Recently, researchers have put effort into developing new functionalization strategies and technologies which provide efficient immobilization and stability of any sort of molecule. Here, we present an overview of the most widely used methods of surface functionalization of microarray substrates, as well as the most recent advances in the field, and compare their performance in terms of optimal immobilization of the bioreceptor molecules. We focus on label-free microarrays and, in particular, we aim to describe the impact of surface chemistry on two types of microarray-based sensors: microarrays for single particle imaging and for label-free measurements of binding kinetics. Both protein and DNA microarrays are taken into consideration, and the effect of different polymeric coatings on the molecules’ functionalities is critically analyzed.

2019 ◽  
Vol 9 (1) ◽  
pp. 158 ◽  
Author(s):  
Renaud G. Rinaldi ◽  
Lionel Manin ◽  
Sébastien Moineau ◽  
Nicolas Havard

The performance of a table tennis racket is often associated with subjective or quantitative criteria such as the adhesion, the control and the speed. Overall, the so-called performance aims at characterizing the impact with the ball. Ultimately, the polymeric layers glued onto the wooden blade play a key role, as evidenced in a previous work where the normal linear (no spin) impact of a ball onto polymeric layers was experimentally and numerically investigated. In this work, more realistic loading conditions leading to varying the incident angle and spin of the ball, were explored. While the sole linear restitution coefficient was determined in the anterior normal impact study, new physical metrics were identified to describe fully the trajectory of the reflected ball after impact. A companion 3D finite elements model was developed where the polymeric time-dependent dissipative compliant behavior measured with dynamic mechanical analysis and compression tests was accounted for. The confrontations with the experimental data highlighted the key role of the polymer intrinsic properties along with the friction coefficient between the ball and the polymer external layer.


IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 560-568 ◽  
Author(s):  
Carsten Fortmann-Grote ◽  
Alexey Buzmakov ◽  
Zoltan Jurek ◽  
Ne-Te Duane Loh ◽  
Liubov Samoylova ◽  
...  

Single-particle imaging with X-ray free-electron lasers (XFELs) has the potential to provide structural information at atomic resolution for non-crystalline biomolecules. This potential exists because ultra-short intense pulses can produce interpretable diffraction data notwithstanding radiation damage. This paper explores the impact of pulse duration on the interpretability of diffraction data using comprehensive and realistic simulations of an imaging experiment at the European X-ray Free-Electron Laser. It is found that the optimal pulse duration for molecules with a few thousand atoms at 5 keV lies between 3 and 9 fs.


Dengue virus (DENV) is a reemerging mosquito-borne disease that is endemic in more than 125 countries, affecting 200 million people per year. Screening testing has been a good attempt to minimize the impact caused by high morbity and mortality rates of DENV. In this study, a simple and disposable label-free electrochemical immunosensor based on a carbon ink graphite screen-printed electrode (SPE) one-step fabricated was developed for detection of non-structural 1 protein (NS1). The SPE surface was modified by drop casting, depositing a colloidal suspension containing amine-functionalized gold nanoparticles (AuNP-NH2). AuNPs were synthetized by a photoinduced physical method, illuminating preformed gold seeds with a light-emitting diode (LED,) at blue region, by using the polyethyleneimine (NH2) as reductor and stabilizing agent. UV-VIS spectroscopy and Transmission Electron Microscopy (TEM) were used to characterize the amine AuNPs. Electrocatalytic activity of AuNPs allowed more sensitivity for a label-free detection of NS1 by square wave voltammetry (SWV), with linear response from 0.1 to 2 µg mL-1. It was found a good linearity (coefficient of correlation of 0.995 (p<0.01) and a limit of detection of 0.03 µg mL-1 NS1 for analytical responses. AuNP-NH2 synthesis provided an easy oriented immobilization of anti-NS1 antibodies by Fc portion, resulting in a simple fabrication immunosensor with relative high performance and feasibility for early diagnostic of DENV.


2021 ◽  
Author(s):  
Arpan De ◽  
Sharmistha Shee ◽  
Subir Kumar Sarkar

Due to limitations of Silicon, Transition metal dichalcogenides (TMD) based biosensors are popular in the recent times. In TMD family, Molybdenum telluride (MoTe2) is being studied a lot for different biosensing application. However, for DNA detection using TMD based DMFET, the effect of the electrical variations in DNA has not been studied before. Also, the impact of DNA-Electrode interaction on transducer level of DMFET is yet to be studied. In this article, we have proposed a Molybdenum telluride (MoTe2) based Accumulation Mode Field Effect Transistor (AMFET) for possible dielectric modulated biosensing application. The study is focused on DNA detection including the electric variations of DNA due to surface interaction. We have done a circuit level analysis of the proposed structure for having deeper insights into its performance under various DNA orientations in the nanogap. We have also presented a benchmarking to highlight the superior sensitivity of the proposed structure (∆V<sub>th </sub>= 700mV at K = 8). The impact of back-gate bias is also included. We have obtained significant variation of threshold voltage shift for different orientation in the proposed structure suggesting strong impact of electrical variations in DNA in biosensing performance of MoTe<sub>2</sub> AMFET.


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