scholarly journals Chemocatalytic Amplification Probes Enable Transcriptionally-Regulated Au(I)-Catalysis in E. coli and Sensitive Detection of SARS-CoV-2 RNA Fragments

2020 ◽  
Author(s):  
Sydnee Green ◽  
Benjamin Wigman ◽  
Sepand Nistanaki ◽  
Hayden Montgomery ◽  
Christopher G. Jones ◽  
...  
Keyword(s):  
Transition Metal ◽  
Direct Detection ◽  
Sensitive Detection ◽  
Metal Species ◽  
Reactive Metal ◽  
Hybridization Probe ◽  
Metal Centers ◽  
E Coli ◽  
Rna Fragments ◽  
The Many

<div>The union of transition metal catalysis with native biochemistry presents a powerful opportunity</div><div>to perform abiotic reactions within complex biological systems.(1,2) However, several chemical</div><div>compatibility challenges associated with incorporating reactive metal centers into complex</div><div>biological environments have hindered efforts in this area, despite the many opportunities it may</div><div>present. More challenging than chemical compatibility is biocommunicative transition metal</div><div>catalysis, where the reactivity of the metal species is regulated by native biological stimuli, akin</div><div>to natural biocatalytic processes. Here we report a novel Au(I)-DNAzyme that is activated by short</div><div>nucleic acids in a highly sequence-specific manner and that is compatible with complex biological</div><div>matrices. The active Au(I)-DNAzyme catalyzes the formation of a fluorescent molecule with >10</div><div>turnovers. This functional allostery, resulting in chemocatalytic signal amplification, is competent</div><div>in complex biological settings, including within recombinant E. coli cells, where the catalytic</div><div>activity of the Au(I)-DNAzyme is regulated by transcription of an inducible plasmid. We further</div><div>demonstrate the potential of this transition metal oligonucleotide complex as a highly sensitive and</div><div>selective hybridization probe, permitting the detection of attomolar concentrations (ca. 60</div><div>molecules/µL) of SARS-CoV-2 RNA gene fragments in simulated biological matrices with ≥85%</div><div>accuracy. Notably, this sensitive detection platform avoids expensive and poorly-scalable</div><div>biochemical components (e.g. post-synthetically modified oligonucleotides or enzymes) and</div><div>utilizes small molecule fluorophores, inexpensive Au salts and oligonucleotides composed of</div><div>canonical bases. This discovery highlights promising opportunities to perform abiotic catalysis in</div><div>complex biological settings under transcriptional regulation, as well as a chemocatalytic strategy</div><div>for PCR-free, direct-detection of RNA and DNA.</div><div><br></div>

scholarly journals Chemocatalytic Amplification Probes Enable Transcriptionally-Regulated Au(I)-Catalysis in E. coli and Sensitive Detection of SARS-CoV-2 RNA Fragments

2020 ◽  
Author(s):  
Sydnee Green ◽  
Benjamin Wigman ◽  
Sepand Nistanaki ◽  
Hayden Montgomery ◽  
Christopher G. Jones ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Catalysis ◽  
Sensitive Detection ◽  
Metal Species ◽  
Chemical Compatibility ◽  
Biological Matrices ◽  
Reactive Metal ◽  
Hybridization Probe ◽  
Metal Catalysis ◽  
E Coli

<div>The union of transition metal catalysis with native biochemistry presents a powerful opportunity</div><div>to perform abiotic reactions within complex biological systems.(1,2) However, several chemical</div><div>compatibility challenges associated with incorporating reactive metal centers into complex</div><div>biological environments have hindered efforts in this area, despite the many opportunities it may</div><div>present. More challenging than chemical compatibility is biocommunicative transition metal</div><div>catalysis, where the reactivity of the metal species is regulated by native biological stimuli, akin</div><div>to natural biocatalytic processes. Here we report a novel Au(I)-DNAzyme that is activated by short</div><div>nucleic acids in a highly sequence-specific manner and that is compatible with complex biological</div><div>matrices. The active Au(I)-DNAzyme catalyzes the formation of a fluorescent molecule with >10</div><div>turnovers. This functional allostery, resulting in chemocatalytic signal amplification, is competent</div><div>in complex biological settings, including within recombinant E. coli cells, where the catalytic</div><div>activity of the Au(I)-DNAzyme is regulated by transcription of an inducible plasmid. We further</div><div>demonstrate the potential of this transition metal oligonucleotide complex as a highly sensitive and</div><div>selective hybridization probe, permitting the detection of attomolar concentrations (ca. 60</div><div>molecules/µL) of SARS-CoV-2 RNA gene fragments in simulated biological matrices with ≥85%</div><div>accuracy. Notably, this sensitive detection platform avoids expensive and poorly-scalable</div><div>biochemical components (e.g. post-synthetically modified oligonucleotides or enzymes) and</div><div>utilizes small molecule fluorophores, inexpensive Au salts and oligonucleotides composed of</div><div>canonical bases. This discovery highlights promising opportunities to perform abiotic catalysis in</div><div>complex biological settings under transcriptional regulation, as well as a chemocatalytic strategy</div><div>for PCR-free, direct-detection of RNA and DNA.</div><div><br></div><p>The union of transition metal catalysis with native biochemistry presents a powerful opportunity to perform abiotic reactions within complex biological systems. However, several chemical compatibility challenges associated with incorporating reactive metal centers into complex biological environments have hindered efforts in this area, despite the many opportunities it may present. More challenging than chemical compatibility is biocommunicative transition metal catalysis, where the reactivity of the metal species is regulated by native biological stimuli, akin to natural biocatalytic processes. Here we report a novel Au(I)-DNAzyme that is activated by short nucleic acids in a highly sequence-specific manner and that is compatible with complex biological matrices. The active Au(I)-DNAzyme catalyzes the formation of a fluorescent molecule with >10 turnovers. This functional allostery, resulting in chemocatalytic signal amplification, is competent in complex biological settings, including within recombinant <i>E. coli </i>cells, where the catalytic activity of the Au(I)-DNAzyme is regulated by transcription of an inducible plasmid. We further demonstrate the potential of this transition metal oligonucleotide complex as a highly sensitive and selective hybridization probe, permitting the detection of attomolar concentrations (<i>ca.</i> 60 molecules/ L) of SARS-CoV-2 RNA gene fragments in simulated biological matrices with ≥85% accuracy. Notably, this sensitive detection platform avoids expensive and poorly-scalable biochemical components (e.g. post-synthetically modified oligonucleotides or enzymes) and utilizes small molecule fluorophores, inexpensive Au salts and oligonucleotides composed of canonical bases. This discovery highlights promising opportunities to perform abiotic catalysis in complex biological settings under transcriptional regulation, as well as a chemocatalytic strategy for PCR-free, direct-detection of RNA and DNA.</p>

scholarly journals Chemocatalytic Amplification Probes Enable Transcriptionally-Regulated Au(I)-Catalysis in E. coli and Sensitive Detection of SARS-CoV-2 RNA Fragments

2020 ◽  
Author(s):  
Sydnee Green ◽  
Benjamin Wigman ◽  
Sepand Nistanaki ◽  
Hayden Montgomery ◽  
Christopher G. Jones ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Catalysis ◽  
Sensitive Detection ◽  
Metal Species ◽  
Chemical Compatibility ◽  
Biological Matrices ◽  
Reactive Metal ◽  
Hybridization Probe ◽  
Metal Catalysis ◽  
E Coli

<div>The union of transition metal catalysis with native biochemistry presents a powerful opportunity</div><div>to perform abiotic reactions within complex biological systems.(1,2) However, several chemical</div><div>compatibility challenges associated with incorporating reactive metal centers into complex</div><div>biological environments have hindered efforts in this area, despite the many opportunities it may</div><div>present. More challenging than chemical compatibility is biocommunicative transition metal</div><div>catalysis, where the reactivity of the metal species is regulated by native biological stimuli, akin</div><div>to natural biocatalytic processes. Here we report a novel Au(I)-DNAzyme that is activated by short</div><div>nucleic acids in a highly sequence-specific manner and that is compatible with complex biological</div><div>matrices. The active Au(I)-DNAzyme catalyzes the formation of a fluorescent molecule with >10</div><div>turnovers. This functional allostery, resulting in chemocatalytic signal amplification, is competent</div><div>in complex biological settings, including within recombinant E. coli cells, where the catalytic</div><div>activity of the Au(I)-DNAzyme is regulated by transcription of an inducible plasmid. We further</div><div>demonstrate the potential of this transition metal oligonucleotide complex as a highly sensitive and</div><div>selective hybridization probe, permitting the detection of attomolar concentrations (ca. 60</div><div>molecules/µL) of SARS-CoV-2 RNA gene fragments in simulated biological matrices with ≥85%</div><div>accuracy. Notably, this sensitive detection platform avoids expensive and poorly-scalable</div><div>biochemical components (e.g. post-synthetically modified oligonucleotides or enzymes) and</div><div>utilizes small molecule fluorophores, inexpensive Au salts and oligonucleotides composed of</div><div>canonical bases. This discovery highlights promising opportunities to perform abiotic catalysis in</div><div>complex biological settings under transcriptional regulation, as well as a chemocatalytic strategy</div><div>for PCR-free, direct-detection of RNA and DNA.</div><div><br></div><p>The union of transition metal catalysis with native biochemistry presents a powerful opportunity to perform abiotic reactions within complex biological systems. However, several chemical compatibility challenges associated with incorporating reactive metal centers into complex biological environments have hindered efforts in this area, despite the many opportunities it may present. More challenging than chemical compatibility is biocommunicative transition metal catalysis, where the reactivity of the metal species is regulated by native biological stimuli, akin to natural biocatalytic processes. Here we report a novel Au(I)-DNAzyme that is activated by short nucleic acids in a highly sequence-specific manner and that is compatible with complex biological matrices. The active Au(I)-DNAzyme catalyzes the formation of a fluorescent molecule with >10 turnovers. This functional allostery, resulting in chemocatalytic signal amplification, is competent in complex biological settings, including within recombinant <i>E. coli </i>cells, where the catalytic activity of the Au(I)-DNAzyme is regulated by transcription of an inducible plasmid. We further demonstrate the potential of this transition metal oligonucleotide complex as a highly sensitive and selective hybridization probe, permitting the detection of attomolar concentrations (<i>ca.</i> 60 molecules/ L) of SARS-CoV-2 RNA gene fragments in simulated biological matrices with ≥85% accuracy. Notably, this sensitive detection platform avoids expensive and poorly-scalable biochemical components (e.g. post-synthetically modified oligonucleotides or enzymes) and utilizes small molecule fluorophores, inexpensive Au salts and oligonucleotides composed of canonical bases. This discovery highlights promising opportunities to perform abiotic catalysis in complex biological settings under transcriptional regulation, as well as a chemocatalytic strategy for PCR-free, direct-detection of RNA and DNA.</p>

Methane activation by ZSM-5-supported transition metal centers

2021 ◽  
Author(s):  
Daniyal Kiani ◽  
Sagar Sourav ◽  
Yadan Tang ◽  
Jonas Baltrusaitis ◽  
Israel E. Wachs
Keyword(s):  
Transition Metal ◽  
Methane Activation ◽  
Group V ◽  
Metal Centers ◽  
Methane Dehydroaromatization

The literature on methane dehydroaromatization (MDA) to benzene using ZSM-5 supported, group V–VIII transition metal-based catalysts (MOx/ZSM-5) is critically reviewed with a focus on in situ and operando molecular insights.

Bacterial detection and differentiation via direct volatile organic compound sensing with surface enhanced Raman spectroscopy

2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bacterial Infections ◽  
Direct Detection ◽  
Point Of Care ◽  
Surface Enhanced Raman Spectroscopy ◽  
E Coli ◽  
Recent Emergence ◽  
Surface Enhanced ◽  
Volatile Organic ◽  
Surface Enhanced Raman

Through the direct detection of bacterial volatile organic compounds (VOCs), via surface enhanced Raman spectroscopy (SERS), we report here a reconfigurable assay for the identification and monitoring of bacteria. We demonstrate differentiation between highly clinically relevant organisms: <i>Escherichia coli</i>, <i>Enterobacter cloacae</i>, and <i>Serratia marcescens</i>. This is the first differentiation of bacteria via SERS of bacterial VOC signatures. The assay also detected as few as 10 CFU/ml of <i>E. coli</i> in under 12 hrs, and detected <i>E. coli</i> from whole human blood and human urine in 16 hrs at clinically relevant concentrations of 10<sup>3</sup> CFU/ml and 10<sup>4</sup> CFU/ml, respectively. In addition, the recent emergence of portable Raman spectrometers uniquely allows SERS to bring VOC detection to point-of-care settings for diagnosing bacterial infections.

Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

2019 ◽  
Vol 16 (1) ◽  
pp. 173-180
Author(s):  
Mingwei Chen ◽  
Jinyu Hu ◽  
Xiaoli Tang ◽  
Qiming Zhu
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Metal Species ◽  
Good Substrate ◽  
Active Metal ◽  
Homocoupling Reaction ◽  
Catalytic Cycles ◽  
Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

Dioxygen splitting at room temperature over distant binuclear transition metal centers in zeolites for direct oxidation of methane to methanol

2021 ◽  
Author(s):  
Kinga Mlekodaj ◽  
Mariia Lemishka ◽  
Stepan Sklenak ◽  
Jiri Dedecek ◽  
Edyta Tabor
Keyword(s):  
Transition Metal ◽  
Room Temperature ◽  
Direct Oxidation ◽  
Metal Centers ◽  
Oxidation Of Methane ◽  
First Time

Here we demonstrate for the first time the splitting of dioxygen at RT over distant binuclear transition metal (M = Ni, Mn, and Co) centers stabilized in ferrierite zeolite. Cleaved...

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