Spinach-based fluorescent light-up biosensors for multiplexed and label-free detection of microRNAs

2018 ◽  
Vol 54 (24) ◽  
pp. 3010-3013 ◽  
Author(s):  
Zhan-Ming Ying ◽  
Bin Tu ◽  
Lan Liu ◽  
Hao Tang ◽  
Li-Juan Tang ◽  
...  
Keyword(s):  
Fluorescent Light ◽  
Label Free ◽  
Microrna Detection ◽  
Transcription Process ◽  
Label Free Detection

A novel Spinach-based fluorescent light-up biosensor utilizing the T7 in vitro transcription process to generate unmodified Spinach sequences for multiplexed microRNA detection has been developed.

Y-shaped probe for convenient and label-free detection of microRNA-21 in vitro

2016 ◽  
Vol 499 ◽  
pp. 8-14 ◽  
Author(s):  
Kui He ◽  
Rong Liao ◽  
Changqun Cai ◽  
Caishuang Liang ◽  
Chan Liu ◽  
...  
Keyword(s):  
Label Free ◽  
Label Free Detection

scholarly journals An Innovative Cell Microincubator for Drug Discovery Based on 3D Silicon Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Francesca Aredia ◽  
Francesca Carpignano ◽  
Salvatore Surdo ◽  
Giuseppe Barillaro ◽  
Giuliano Mazzini ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Tumor Cells ◽  
Three Dimensional ◽  
Label Free ◽  
Core Element ◽  
Great Ability ◽  
Label Free Detection ◽  
Ht1080 Cells ◽  
Power Radiation

We recently employed three-dimensional (3D) silicon microstructures (SMSs) consisting in arrays of 3 μm-thick silicon walls separated by 50 μm-deep, 5 μm-wide gaps, as microincubators for monitoring the biomechanical properties of tumor cells. They were here applied to investigate the in vitro behavior of HT1080 human fibrosarcoma cells driven to apoptosis by the chemotherapeutic drug Bleomycin. Our results, obtained by fluorescence microscopy, demonstrated that HT1080 cells exhibited a great ability to colonize the narrow gaps. Remarkably, HT1080 cells grown on 3D-SMS, when treated with the DNA damaging agent Bleomycin under conditions leading to apoptosis, tended to shrink, reducing their volume and mimicking the normal behavior of apoptotic cells, and were prone to leave the gaps. Finally, we performed label-free detection of cells adherent to the vertical silicon wall, inside the gap of 3D-SMS, by exploiting optical low coherence reflectometry using infrared, low power radiation. This kind of approach may become a new tool for increasing automation in the drug discovery area. Our results open new perspectives in view of future applications of the 3D-SMS as the core element of a lab-on-a-chip suitable for screening the effect of new molecules potentially able to kill tumor cells.

scholarly journals PfHRP2 detection using plasmonic optrodes: performance analysis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Médéric Loyez ◽  
Mathilde Wells ◽  
Stéphanie Hambÿe ◽  
François Hubinon ◽  
Bertrand Blankert ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Limit Of Detection ◽  
Fiber Surface ◽  
Malaria Diagnosis ◽  
High Sensitivity ◽  
Cost Effective ◽  
Label Free ◽  
Multiple Receptors ◽  
Label Free Detection

Abstract Background Early malaria diagnosis and its profiling require the development of new sensing platforms enabling rapid and early analysis of parasites in blood or saliva, aside the widespread rapid diagnostic tests (RDTs). Methods This study shows the performance of a cost-effective optical fiber-based solution to target the presence of Plasmodium falciparum histidine-rich protein 2 (PfHRP2). Unclad multimode optical fiber probes are coated with a thin gold film to excite Surface Plasmon Resonance (SPR) yielding high sensitivity to bio-interactions between targets and bioreceptors grafted on the metal surface. Results Their performances are presented in laboratory conditions using PBS spiked with growing concentrations of purified target proteins and within in vitro cultures. Two probe configurations are studied through label-free detection and amplification using secondary antibodies to show the possibility to lower the intrisic limit of detection. Conclusions As malaria hits millions of people worldwide, the improvement and multiplexing of this optical fiber technique can be of great interest, especially for a future purpose of using multiple receptors on the fiber surface or several coated-nanoparticles as amplifiers.

scholarly journals Distinguishing dopamine and calcium responses using XNA-nanotube sensors for improved neurochemical sensing

2021 ◽  
Author(s):  
Alice J. Gillen ◽  
Alessandra Antonucci ◽  
Melania Reggente ◽  
Daniel Morales ◽  
Ardemis A. Boghossian
Keyword(s):  
Neurological Diseases ◽  
Locked Nucleic Acid ◽  
Optical Biosensors ◽  
Label Free ◽  
Sensing Applications ◽  
Label Free Detection ◽  
Improved Stability ◽  
New Applications

AbstractTo date, the engineering of single-stranded DNA-SWCNT (DNA-SWCNT) optical biosensors have largely focused on creating sensors for new applications with little focus on optimising existing sensors for in vitro and in vivo conditions. Recent studies have shown that nanotube fluorescence can be severely impacted by changes in local cation concentrations. This is particularly problematic for neurotransmitter sensing applications as spatial and temporal fluctuations in the concentration of cations, such as Na+, K+, or Ca2+, play a central role in neuromodulation. This can lead to inaccuracies in the determination of neurotransmitter concentrations using DNA-SWCNT sensors, which limits their use for detecting and treating neurological diseases.Herein, we present new approaches using locked nucleic acid (LNA) to engineer SWCNT sensors with improved stability towards cation-induced fluorescence changes. By incorporating LNA bases into the (GT)15-DNA sequence, we create sensors that are not only more resistant towards undesirable fluorescence modulation in the presence of Ca2+ but that also retain their capabilities for the label-free detection of dopamine. The synthetic biology approach presented in this work therefore serves as a complementary means for enhancing nanotube optoelectronic behavior, unlocking previously unexplored possibilities for developing nano-bioengineered sensors with augmented capabilities.

scholarly journals Applications of Raman Spectroscopy in Bacterial Infections: Principles, Advantages, and Shortcomings

2021 ◽  
Vol 12 ◽  
Author(s):  
Liang Wang ◽  
Wei Liu ◽  
Jia-Wei Tang ◽  
Jun-Jiao Wang ◽  
Qing-Hua Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Antibiotic Resistance ◽  
Infectious Diseases ◽  
Bacterial Infections ◽  
Bacterial Pathogens ◽  
Basic Research ◽  
Label Free ◽  
Clinical Implementation ◽  
Label Free Detection

Infectious diseases caused by bacterial pathogens are important public issues. In addition, due to the overuse of antibiotics, many multidrug-resistant bacterial pathogens have been widely encountered in clinical settings. Thus, the fast identification of bacteria pathogens and profiling of antibiotic resistance could greatly facilitate the precise treatment strategy of infectious diseases. So far, many conventional and molecular methods, both manual or automatized, have been developed for in vitro diagnostics, which have been proven to be accurate, reliable, and time efficient. Although Raman spectroscopy (RS) is an established technique in various fields such as geochemistry and material science, it is still considered as an emerging tool in research and diagnosis of infectious diseases. Based on current studies, it is too early to claim that RS may provide practical guidelines for microbiologists and clinicians because there is still a gap between basic research and clinical implementation. However, due to the promising prospects of label-free detection and noninvasive identification of bacterial infections and antibiotic resistance in several single steps, it is necessary to have an overview of the technique in terms of its strong points and shortcomings. Thus, in this review, we went through recent studies of RS in the field of infectious diseases, highlighting the application potentials of the technique and also current challenges that prevent its real-world applications.

Nanomechanical Microcantilevers for In-Vitro Biomolecular Detection

2007 ◽  
Author(s):  
Kilho Eom ◽  
Tae Yun Kwon ◽  
Jinsung Park ◽  
Sungsoo Na ◽  
Dae Sung Yoon ◽  
...  
Keyword(s):  
Real Time ◽  
Biological Molecules ◽  
Label Free ◽  
Biomolecular Detection ◽  
Label Free Detection ◽  
Detection Of Biomolecules ◽  
Kinetics Of ◽  
Insight Into

Nanomechanical microcantilevers have enabled the sensitive label-free detection of chemical and/or biological molecules. In recent years, resonating microcantilevers have achieved the unprecedented sensitivity in detecting molecules. In this article, we review our current works on the label-free detection of biomolecules based on resonating microcantilevers. Our piezoelectric thick film microcantilevers exhibit the relatively high quality factor in a viscous liquid, indicating the potential of our cantilever to in situ biosensor applications for real-time detection of biomolecular interactions. It is shown that our microcantilevers allow the noise-free real-time monitoring of biomolecular recognitions, providing the insight into kinetics of biomolecular recognitions.

scholarly journals Label-free detection of transporter activity via GPCR signalling in living cells: A case for SLC29A1, the equilibrative nucleoside transporter 1

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Vlachodimou ◽  
Adriaan P. IJzerman ◽  
Laura H. Heitman
Keyword(s):  
Nucleoside Transporter ◽  
Label Free ◽  
Extracellular Adenosine ◽  
Equilibrative Nucleoside Transporter ◽  
Human Osteosarcoma Cells ◽  
Adenosine Concentration ◽  
Label Free Detection ◽  
Solute Carrier ◽  
G Protein Coupled

Abstract Transporters are important therapeutic but yet understudied targets due to lack of available assays. Here we describe a novel label-free, whole-cell method for the functional assessment of Solute Carrier (SLC) inhibitors. As many SLC substrates are also ligands for G protein-coupled receptors (GPCRs), transporter inhibition may affect GPCR signalling due to a change in extracellular concentration of the substrate/ligand, which can be monitored by an impedance-based label-free assay. For this study, a prototypical SLC/GPCR pair was selected, i.e. the equilibrative nucleoside transporter-1 (SLC29A1/ENT1) and an adenosine receptor (AR), for which adenosine is the substrate/ligand. ENT1 inhibition with three reference compounds was monitored sensitively via AR activation on human osteosarcoma cells. Firstly, the inhibitor addition resulted in an increased apparent potency of adenosine. Secondly, all inhibitors concentration-dependently increased the extracellular adenosine concentration, resulting in an indirect quantitative assessment of their potencies. Additionally, AR activation was abolished by AR antagonists, confirming that the monitored impedance was AR-mediated. In summary, we developed a novel assay as an in vitro model system that reliably assessed the potency of SLC29A1 inhibitors via AR signalling. As such, the method may be applied broadly as it has the potential to study a multitude of SLCs via concomitant GPCR signalling.

scholarly journals Novel DNA Aptameric Sensors to Detect the Toxic Insecticide Fenitrothion

2021 ◽  
Vol 22 (19) ◽  
pp. 10846
Author(s):  
Kien Hong Trinh ◽  
Ulhas Sopanrao Kadam ◽  
Jinnan Song ◽  
Yuhan Cho ◽  
Chang Ho Kang ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
High Specificity ◽  
Cross Reactivity ◽  
Dna Aptamers ◽  
Label Free ◽  
Wide Range ◽  
Label Free Detection ◽  
Detection Mode ◽  
Aptamer Sensor

Fenitrothion is an insecticide belonging to the organophosphate family of pesticides that is widely used around the world in agriculture and living environments. Today, it is one of the most hazardous chemicals that causes severe environmental pollution. However, detection of fenitrothion residues in the environment is considered a significant challenge due to the small molecule nature of the insecticide and lack of molecular recognition elements that can detect it with high specificity. We performed in vitro selection experiments using the SELEX process to isolate the DNA aptamers that can bind to fenitrothion. We found that newly discovered DNA aptamers have a strong ability to distinguish fenitrothion from other organophosphate insecticides (non-specific targets). Furthermore, we identified a fenitrothion-specific aptamer; FenA2, that can interact with Thioflavin T (ThT) to produce a label-free detection mode with a Kd of 33.57 nM (9.30 ppb) and LOD of 14 nM (3.88 ppb). Additionally, the FenA2 aptamer exhibited very low cross-reactivity with non-specific targets. This is the first report showing an aptamer sensor with a G4-quadruplex-like structure to detect fenitrothion. Moreover, these aptamers have the potential to be further developed into analytical tools for real-time detection of fenitrothion from a wide range of samples.

scholarly journals PCR-free, label-free detection of sequence-specific DNA with single-molecule sensitivity using in vitro N-hybrid system in microfluidic drops

2022 ◽  
Author(s):  
Yizhe Zhang ◽  
David A Weitz
Keyword(s):  
Single Molecule ◽  
High Specificity ◽  
Label Free ◽  
Hybrid Strategy ◽  
Single Molecule Level ◽  
Target Dna ◽  
Label Free Detection ◽  
Novel Method ◽  
Picoliter Droplet

We propose a novel method that can detect DNA with high specificity at the single-molecule level by employing the in vitro N-hybrid strategy realized in sub-picoliter microfluidic drops. It detects target DNA based on the specific interactions of the target-encoded proteins with their partner molecules, and achieves single-molecule sensitivity via signal-transduction and signal-amplification during gene-expression processes in a sub-picoliter droplet, therefore effectively avoiding complicated procedures in labeling-based methods or biases and artifacts in PCR-based methods.

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