A facile water-stable MOF-based “off–on” fluorescent switch for label-free detection of dopamine in biological fluid

2017 ◽  
Vol 5 (13) ◽  
pp. 2524-2535 ◽  
Author(s):  
Yue Cheng ◽  
Jie Wu ◽  
Chao Guo ◽  
Xin-Ge Li ◽  
Bin Ding ◽  
...  
Keyword(s):  
Surface Modification ◽  
Biological Fluid ◽  
Label Free ◽  
Fluorescent Switch ◽  
Label Free Detection

An Abtz–CdI2–MOF was developed as an “off–on” fluorescent switch for label-free detection of dopamine without any surface modification or functionalization.

scholarly journals Study of the Fabrication Technology of Hybrid Microfluidic Biochips for Label-Free Detection of Proteins

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 20
Author(s):  
Nikita Sitkov ◽  
Tatiana Zimina ◽  
Alexey Kolobov ◽  
Evgeny Sevostyanov ◽  
Valentina Trushlyakova ◽  
...  
Keyword(s):  
Technological Process ◽  
Biological Fluid ◽  
Protein Structures ◽  
Microfluidic System ◽  
Diagnostic Tools ◽  
Fluorometric Detection ◽  
Label Free ◽  
Protein Markers ◽  
Label Free Detection ◽  
Microfluidic Biochips

A study of the peculiarities and a comparative analysis of the technologies used for the fabrication of elements of novel hybrid microfluidic biochips for express biomedical analysis have been carried out. The biochips were designed with an incorporated microfluidic system, which enabled an accumulation of the target compounds in a biological fluid to be achieved, thus increasing the biochip system’s sensitivity and even implementing a label-free design of the detection unit. The multilevel process of manufacturing a microfluidic system of a given topology for label-free fluorometric detection of protein structures is presented. The technological process included the chemical modification of the working surface of glass substrates by silanization using (3-aminopropyl) trimethoxysilane (APTMS), formation of the microchannels, for which SU-8 technologies and a last generation dry film photoresist were studied and compared. The solid-state phosphor layers were deposited using three methods: drop application; airbrushing; and mechanical spraying onto the adhesive surface. The processes of sealing the system, installing input ports, and packaging using micro-assembly technologies are described. The technological process has been optimized and the biochip was implemented and tested. The presented system can be used to design novel high-performance diagnostic tools that implement the function of express detection of protein markers of diseases and create low-power multimodal, highly intelligent portable analytical decision-making systems in medicine.

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
Keyword(s):  
Surface Chemistry ◽  
Surface Functionalization ◽  
Dna Microarrays ◽  
Label Free ◽  
Polymeric Coatings ◽  
Label Free Detection ◽  
Particle Imaging ◽  
Single Particle Imaging ◽  
The Impact

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.

scholarly journals Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1872
Author(s):  
Holger Schulze ◽  
Harry Wilson ◽  
Ines Cara ◽  
Steven Carter ◽  
Edward N. Dyson ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Electrochemical Impedance ◽  
Point Of Care ◽  
Branched Polymers ◽  
Label Free ◽  
Conformation Change ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Staphylococcus Carnosus ◽  
Label Free Detection

Rapid point of care tests for bacterial infection diagnosis are of great importance to reduce the misuse of antibiotics and burden of antimicrobial resistance. Here, we have successfully combined a new class of non-biological binder molecules with electrochemical impedance spectroscopy (EIS)-based sensor detection for direct, label-free detection of Gram-positive bacteria making use of the specific coil-to-globule conformation change of the vancomycin-modified highly branched polymers immobilized on the surface of gold screen-printed electrodes upon binding to Gram-positive bacteria. Staphylococcus carnosus was detected after just 20 min incubation of the sample solution with the polymer-functionalized electrodes. The polymer conformation change was quantified with two simple 1 min EIS tests before and after incubation with the sample. Tests revealed a concentration dependent signal change within an OD600 range of Staphylococcus carnosus from 0.002 to 0.1 and a clear discrimination between Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. This exhibits a clear advancement in terms of simplified test complexity compared to existing bacteria detection tests. In addition, the polymer-functionalized electrodes showed good storage and operational stability.

H2O2-sensitive quantum dots for the label-free detection of glucose

Talanta ◽  
2010 ◽  
Vol 82 (3) ◽  
pp. 997-1002 ◽  
Author(s):  
Mei Hu ◽  
Jing Tian ◽  
Hao-Ting Lu ◽  
Li-Xing Weng ◽  
Lian-Hui Wang
Keyword(s):  
Quantum Dots ◽  
Label Free ◽  
Label Free Detection

scholarly journals Affinity Sensors for the Diagnosis of COVID-19

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 390
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Arunas Ramanavicius
Keyword(s):  
Field Effect Transistors ◽  
Resonance Field ◽  
Analytical Signal ◽  
Nucleic Acid Hybridization ◽  
Detection Methods ◽  
Label Free ◽  
Infected People ◽  
Label Free Detection ◽  
Main Instrument ◽  
Antigen Antibody

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxygen species (ROS) level are mostly used for the generation of analytical signals, which can be accurately measured by electrochemical, optical, surface plasmon resonance, field-effect transistors, and some other methods and transducers. Electrochemical biosensors are the most consistent with the general trend towards, acceleration, and simplification of the bioanalytical process. These biosensors mostly are based on the determination of antigen-antibody interaction and are robust, sensitive, accurate, and sometimes enable label-free detection of an analyte. Along with the specification of biosensors, we also provide a brief overview of generally used testing techniques, and the description of the structure, life cycle and immune host response to SARS-CoV-2, and some deeper details of analytical signal detection principles.

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