scholarly journals Programmable receptors enable bacterial biosensors to detect pathological biomarkers in clinical samples

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hung-Ju Chang ◽  
Ana Zúñiga ◽  
Ismael Conejero ◽  
Peter L. Voyvodic ◽  
Jerome Gracy ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Clinical Samples ◽  
Monitoring And Control ◽  
Modular Assembly ◽  
E Coli ◽  
Naked Eye ◽  
Synthetic Receptor ◽  
And Control ◽  
Do So

AbstractBacterial biosensors, or bactosensors, are promising agents for medical and environmental diagnostics. However, the lack of scalable frameworks to systematically program ligand detection limits their applications. Here we show how novel, clinically relevant sensing modalities can be introduced into bactosensors in a modular fashion. To do so, we have leveraged a synthetic receptor platform, termed EMeRALD (Engineered Modularized Receptors Activated via Ligand-induced Dimerization) which supports the modular assembly of sensing modules onto a high-performance, generic signaling scaffold controlling gene expression in E. coli. We apply EMeRALD to detect bile salts, a biomarker of liver dysfunction, by repurposing sensing modules from enteropathogenic Vibrio species. We improve the sensitivity and lower the limit-of-detection of the sensing module by directed evolution. We then engineer a colorimetric bactosensor detecting pathological bile salt levels in serum from patients having undergone liver transplant, providing an output detectable by the naked-eye. The EMeRALD technology enables functional exploration of natural sensing modules and rapid engineering of synthetic receptors for diagnostics, environmental monitoring, and control of therapeutic microbes.

scholarly journals A synthetic receptor platform enables rapid and portable monitoring of liver dysfunction via engineered bacteria.

2021 ◽  
Author(s):  
Hung-Ju Chang ◽  
Ana Zuniga ◽  
Ismael Conejero ◽  
Peter L Voyvodic ◽  
Jerome Gracy ◽  
...  
Keyword(s):  
Liver Dysfunction ◽  
High Performance ◽  
Limit Of Detection ◽  
Portable Monitoring ◽  
Monitoring And Control ◽  
Modular Assembly ◽  
E Coli ◽  
Synthetic Receptor ◽  
And Control ◽  
Engineered Bacteria

Bacterial biosensors, or bactosensors, are promising field-deployable agents for medical and environmental diagnostics. However, the lack of scalable frameworks to systematically program ligand detection limits their applications. Here we present a synthetic receptor platform, termed EMeRALD (Engineered Modularized Receptors Activated via Ligand-induced Dimerization) which supports the modular assembly of sensing modules onto a high-performance, generic signaling scaffold controlling gene expression in E. coli. We applied EMeRALD to detect bile salts, a biomarker of liver dysfunction, by repurposing sensing modules from enteropathogenic Vibrio species. We improved the sensitivity and lowered the limit-of-detection of the sensing module by directed evolution. We then engineered a colorimetric bactosensor detecting pathological bile salt levels in serum from patients having undergone liver transplant, providing an output detectable by the naked-eye. The EMeRALD technology enables functional exploration of natural sensing modules and rapid engineering of synthetic receptors for diagnostics, environmental monitoring, and control of therapeutic microbes.

scholarly journals A synthetic receptor platform enables rapid and portable monitoring of liver dysfunction via engineered bacteria.

2021 ◽  
Author(s):  
Hung-Ju Chang ◽  
Ana Zuniga ◽  
Ismael Conejero ◽  
Peter Voyvodic ◽  
Jerome Gracy ◽  
...  
Keyword(s):  
Liver Dysfunction ◽  
High Performance ◽  
Limit Of Detection ◽  
Portable Monitoring ◽  
Monitoring And Control ◽  
Modular Assembly ◽  
E Coli ◽  
Synthetic Receptor ◽  
And Control ◽  
Engineered Bacteria

Abstract Bacterial biosensors, or bactosensors, are promising field-deployable agents for medical and environmental diagnostics. However, the lack of scalable frameworks to systematically program ligand detection limits their applications. Here we present a synthetic receptor platform, termed EMeRALD (Engineered Modularized Receptors Activated via Ligand-induced Dimerization) which supports the modular assembly of sensing modules onto a high-performance, generic signaling scaffold controlling gene expression in E. coli. We applied EMeRALD to detect bile salts, a biomarker of liver dysfunction, by repurposing sensing modules from enteropathogenic Vibrio species. We improved the sensitivity and lowered the limit-of-detection of the sensing module by directed evolution. We then engineered a colorimetric bactosensor detecting pathological bile salt levels in serum from patients having undergone liver transplant, providing an output detectable by the naked-eye. The EMeRALD technology enables functional exploration of natural sensing modules and rapid engineering of synthetic receptors for diagnostics, environmental monitoring, and control of therapeutic microbes.

scholarly journals Detection of Antimicrobial Residues in Poultry Litter: Monitoring a Risk through a Selective and Sensitive HPLC–MS/MS Method

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1399
Author(s):  
Karina Yévenes ◽  
Ekaterina Pokrant ◽  
Lina Trincado ◽  
Lisette Lapierre ◽  
Nicolás Galarce ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Poultry Litter ◽  
Chromatography Tandem Mass Spectrometry ◽  
Antimicrobial Residues ◽  
Field Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Commercial Poultry ◽  
Agriculture Fertilizer ◽  
And Control

Tetracyclines, sulphonamides, and quinolones are families of antimicrobials (AMs) widely used in the poultry industry and can excrete up to 90% of AMs administrated, which accumulate in poultry litter. Worryingly, poultry litter is widely used as an agriculture fertilizer, contributing to the spread AMs residues in the environment. The aim of this research was to develop a method that could simultaneously identify and quantify three AMs families in poultry litter by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Samples of AMs free poultry litter were used to validate the method according to 657/2002/EC and VICH GL49. Results indicate that limit of detection (LOD) ranged from 8.95 to 20.86 μg kg−1, while limits of quantitation (LOQ) values were between 26.85 and 62.58 µg kg−1 of tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, enrofloxacin, ciprofloxacin, flumequine, sulfachloropyridazine, and sulfadiazine. Recoveries obtained ranged from 93 to 108%. The analysis of field samples obtained from seven commercial poultry flocks confirmed the adequacy of the method since it detected means concentrations ranging from 20 to 10,364 μg kg−1. This provides us an accurate and reliable tool to monitor AMs residues in poultry litter and control its use as agricultural fertilizer.

scholarly journals Development and evaluation of duplex TaqMan real-time PCR assay for detection and differentiation of wide-type and MGF505-2R gene-deleted African swine fever viruses

2020 ◽  
Author(s):  
zhenhua Guo ◽  
Kunpeng Li ◽  
Songlin Qiao ◽  
Xinxin Chen ◽  
Ruiguang Deng ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Large Scale ◽  
Limit Of Detection ◽  
African Swine Fever ◽  
Economic Losses ◽  
Clinical Samples ◽  
Diagnosis Method ◽  
Pcr Method ◽  
And Control

Abstract Background: African swine fever (ASF) is the most important disease to the pigs and cause serious economic losses to the countries with large-scale swine production. Vaccines are recognized as the most useful tool to prevent and control ASF virus (ASFV) infection. Currently, the MGF505 and MGF360 gene-deleted ASFVs or combined with CD2v deletion were confirmed to be the most promising vaccine candidates. Thus, it is essential to develop a diagnosis method to discriminate wide-type strain from the vaccines used.Results: In this study, we established a duplex TaqMan real-time PCR based on the B646L gene and MGF505-2R gene. The sequence alignment showed that the targeted regions of primers and probes are highly conserved in the genotype II ASFVs. The duplex real-time assay can specifically detect B646L and MGF505-2R gene single or simultaneously without cross-reaction with other porcine viruses tested. The limit of detection was 5.8 copies and 3.0 copies for the standard plasmids containing B646L and MGF505-2R genes, respectively. Clinical samples were tested in parallel by duplex real-time PCR and a commercial ASFV detection kit. The detection results of these two assays against B646L gene were well consistent.Conclusion: We successfully developed and evaluated a duplex TaqMan real-time PCR method which can effectively distinguish the wide type and MGF505 gene-deleted ASFVs. It would be a useful tool for the clinical diagnosis and control of ASF.

scholarly journals Hyperchromatic structural color for perceptually enhanced sensing by the naked eye

2020 ◽  
Vol 117 (48) ◽  
pp. 30107-30117
Author(s):  
Tahmid H. Talukdar ◽  
Bria McCoy ◽  
Sarah K. Timmins ◽  
Taufiquar Khan ◽  
Judson D. Ryckman
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Form Factors ◽  
Optical Filters ◽  
Color Filter ◽  
Structural Color ◽  
Label Free ◽  
Colorimetric Sensing ◽  
Large Area ◽  
Naked Eye

Colorimetric sensors offer the prospect for on-demand sensing diagnostics in simple and low-cost form factors, enabling rapid spatiotemporal inspection by digital cameras or the naked eye. However, realizing strong dynamic color variations in response to small changes in sample properties has remained a considerable challenge, which is often pursued through the use of highly responsive materials under broadband illumination. In this work, we demonstrate a general colorimetric sensing technique that overcomes the performance limitations of existing chromatic and luminance-based sensing techniques. Our approach combines structural color optical filters as sensing elements alongside a multichromatic laser illuminant. We experimentally demonstrate our approach in the context of label-free biosensing and achieve ultrasensitive and perceptually enhanced chromatic color changes in response to refractive index changes and small molecule surface attachment. Using structurally enabled chromaticity variations, the human eye is able to resolve ∼0.1-nm spectral shifts with low-quality factor (e.g., Q ∼ 15) structural filters. This enables spatially resolved biosensing in large area (approximately centimeters squared) lithography-free sensing films with a naked eye limit of detection of ∼3 pg/mm2, lower than industry standard sensors based on surface plasmon resonance that require spectral or angular interrogation. This work highlights the key roles played by both the choice of illuminant and design of structural color filter, and it offers a promising pathway for colorimetric devices to meet the strong demand for high-performance, rapid, and portable (or point-of-care) diagnostic sensors in applications spanning from biomedicine to environmental/structural monitoring.

scholarly journals Polyaniline Nanocomposites for Hydrogen Sulfide Detection at ppb Level

2021 ◽  
Vol 6 (1) ◽  
pp. 69
Author(s):  
Caroline Duc ◽  
Mohamed-Lamine Boukhenane ◽  
Thomas Fagniez ◽  
Nathalie Redon ◽  
Jean-Luc Wojkiewicz
Keyword(s):  
Hydrogen Sulfide ◽  
Tin Oxide ◽  
High Performance ◽  
Limit Of Detection ◽  
Anthropogenic Sources ◽  
Hazardous Substance ◽  
Repeatability And Reproducibility ◽  
New Sensors ◽  
And Control ◽  
Ppm Level

Coming from natural and anthropogenic sources, hydrogen sulfide gas (H2S) is a smelly hazardous substance at the sub-ppm level, which can lead to poisoning deaths at higher concentrations. New sensors with high metrological properties (detection limit lower than 1 ppm) and good stability are still needed to monitor and control the risk associated with this gas. The properties of a high-performance hydrogen sulfide gas sensor based on tin oxide and conductive polymers (polyaniline and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are investigated. The principle of detection of this resistive sensor consists of a two steps reaction. H2S reacts with tin oxide producing hydrochloride acid, which dopes polyaniline, leading to the increase of its conductivity. Those systems present high repeatability and reproducibility, with sensitivities around 10%/ppm and a limit of detection close to 30 ppb. Moreover, the effect of interfering species such as humidity and oxidative gases (ammonia) is addressed. Those species have a limited impact, corrigible by data treatment. Finally, the sensors present an increase of sensitivity with time, apparently due to the modification of the interface between the electrodes and the sensitive materials.

scholarly journals Reconfigurable Multiple Sensing Node for the Automation of Agricultural Field

2019 ◽  
Vol 8 (10) ◽  
pp. 27-31
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Computing System ◽  
Monitoring And Control ◽  
Agricultural Field ◽  
Real Time System ◽  
Agricultural Applications ◽  
High Yields ◽  
External Interface ◽  
And Control

In a real time system, monitoring and control of various parameters of the field is vital .In order to achieve high yields and quality , exact parameters of soils and its necessary inputs to soil need to be put in action. Pest and diseases are also important factors in decline of yield and quality. Considering the various applications of this area, the present paper explains the wireless multi-sensing node for remote monitoring and control system for agricultural applications. This is design with a number of good performance front-end devices and circuits suitable for various types of sensors. Any Sensor device elements can be directly connected without the need of extra circuits. The number of input sensors can be reconfigured with time to time as system demand. The paper describes development and the interface of high performance and low-cost typical features elements. The developed system displayed all the measures field parameters and corresponding set point values on the LCD interface and also are stored in external interface memory for future reference. The developed node can be connected to a personal computing system for decision support using wired RS-232 interface or wireless connectivity using the RF modem from Xbee.

scholarly journals Development and evaluation of duplex TaqMan real-time PCR assay for detection and differentiation of wide-type and MGF505-2R gene-deleted African swine fever viruses

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhenhua Guo ◽  
Kunpeng Li ◽  
Songlin Qiao ◽  
Xin-xin Chen ◽  
Ruiguang Deng ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Large Scale ◽  
Limit Of Detection ◽  
African Swine Fever ◽  
Economic Losses ◽  
Clinical Samples ◽  
Diagnosis Method ◽  
Pcr Method ◽  
And Control

Abstract Background African swine fever (ASF) is the most important disease to the pigs and cause serious economic losses to the countries with large-scale swine production. Vaccines are recognized as the most useful tool to prevent and control ASF virus (ASFV) infection. Currently, the MGF505 and MGF360 gene-deleted ASFVs or combined with CD2v deletion were confirmed to be the most promising vaccine candidates. Thus, it is essential to develop a diagnosis method to discriminate wide-type strain from the vaccines used. Results In this study, we established a duplex TaqMan real-time PCR based on the B646L gene and MGF505-2R gene. The sequence alignment showed that the targeted regions of primers and probes are highly conserved in the genotype II ASFVs. The duplex real-time assay can specifically detect B646L and MGF505-2R gene single or simultaneously without cross-reaction with other porcine viruses tested. The limit of detection was 5.8 copies and 3.0 copies for the standard plasmids containing B646L and MGF505-2R genes, respectively. Clinical samples were tested in parallel by duplex real-time PCR and a commercial ASFV detection kit. The detection results of these two assays against B646L gene were well consistent. Conclusion We successfully developed and evaluated a duplex TaqMan real-time PCR method which can effectively distinguish the wide type and MGF505 gene-deleted ASFVs. It would be a useful tool for the clinical diagnosis and control of ASF.

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