While drinking water disinfection has effectively prevented waterborne diseases, an unintended consequence is the generation of byproducts (DBPs). Epidemiological studies have consistently observed association between consumption chlorinated with increased risk bladder cancer. Out >600 DBPs identified, regulations focus on a few classes, such as trihalomethanes (THMs), whose concentrations were hypothesized to correlate driving toxicity disinfected waters. However, responsible for cancer...

Abstract Synthetic DNA motors have great potential to mimic natural protein in cells but the operation of synthetic living remains challenging and has not been demonstrated. Here we report a DNAzyme motor that operates response specific intracellular target. The whole system is constructed on 20 nm gold nanoparticle (AuNP) decorated with hundreds substrate strands serving as tracks dozens molecules each silenced by locking strand. Intracellular interaction target molecule initiates...

Dynamic DNA assemblies, including catalytic circuits, nanomachines, molecular translators, and reconfigurable nanostructures, have shown promising potential to regulate cell functions, deliver therapeutic reagents, amplify detection signals for diagnostics imaging. However, such applications of dynamic assembly systems been limited nucleic acids a few small molecules, due the approaches trigger assemblies. Herein, we describe binding-induced strand displacement strategy that can convert...

Abstract We introduce the concept and operation of a binding‐induced DNA nanomachine that can be activated by proteins nucleic acids. This new type harnesses specific target binding to trigger assembly separate components are otherwise unable spontaneously assemble. Three‐dimensional tracks high density constructed on gold nanoparticles functionalized with hundreds single‐stranded oligonucleotides tens an affinity ligand. A swing arm, free in solution, is linked second Binding molecule two...

We report the characterization and determination of 2,6-dichloro-1,4-benzoquinone three new disinfection byproducts (DBPs): 2,6-dichloro-3-methyl-1,4-benzoquinone, 2,3,6-trichloro-1,4-benzoquinone, 2,6-dibromo-1,4-benzoquinone. These haloquinones are suspected bladder carcinogens likely produced during drinking water treatment. However, detection these is challenging, consequently, they have not been characterized as DBPs until recently. developed an electrospray ionization tandem mass...

N-Nitrosodimethylamine (NDMA), a member of group probable human carcinogens, has been detected as disinfection byproduct (DBP) in drinking water supplies Canada and the United States. To comprehensively investigate occurrence possible nitrosamines supplies, liquid chromatography-tandem mass spectrometry technique was developed to detect both thermally stable unstable nitrosamines. This consisted solid-phase extraction (SPE), chro matography (LC) separation, tandem quadrupole linear ion trap...

Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition nitrosamine precursors. These treatments included chlorine (OCl−), chloramine (NH2Cl), dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) the ranged from 2 to 24 mg·L−1. disinfected water samples untreated...

Coming clean? Liquid chromatography–ESI tandem mass spectrometry is used to detect 2,6-dichloro-1,4-benzoquinone (see picture) in drinking water treated with chlorine or chloramine.

O157:H7 is a serotype of enterohemorrhagic Escherichia coli (EHEC) and one the major causes food-borne illness. Protection food safety against bacterial contamination rapid diagnosis infection require simple fast assays for detection pathogens, including E. O157:H7. We describe here sensitive assay bacteria by using antibody affinity binding, gold nanoparticle (Au NP) labeling, inductively coupled plasma mass spectrometry (ICPMS) detection. Taking advantage signal amplification property Au...

Exposure to chlorination disinfection byproducts (DBPs) is potentially associated with an increased risk of bladder cancer. Four halobenzoquinones (HBQs) have been detected in treated drinking water and shown potency producing reactive oxygen species inducing damage cellular DNA proteins. These HBQs are unstable water. The fate behavior these distribution systems unclear. Here we report the high-resolution mass spectrometry identification transformation products as...

Single-stranded DNA or RNA aptamer molecules have usually been selected against purified target molecules. To eliminate the need of purifying on cell surface, we developed a selection technique using live bacterial cells in suspension as targets, to select for ssDNA aptamers specific surface Lactobacillus acidophilus were chosen demonstrate proof principle based their high abundance (potential targets). Aptamer pools obtained after 6−8 rounds demonstrated affinity and selective binding with...

Halobenzoquinones (HBQs), a new class of disinfection byproducts (DBPs), occur widely in treated drinking water and recreational water. The main concern regarding human exposure to DBPs stems from epidemiological studies that have consistently linked the consumption chlorinated with an increased risk developing bladder cancer. U.S. Environmental Protection Agency Health Canada set regulations on amount minimize risk. However, these regulated do not account for cancer because they different...

Halobenzoquinones (HBQs) are a class of disinfection byproducts (DBPs) health relevance. In this study, we aimed to uncover which HBQs present in swimming pools. To achieve goal, developed new method capable determining eight while overcoming matrix effects reliable quantification. The provided reproducible and quantitative recovery (67–102%) detection limits 0.03–1.2 ng/L for all HBQs. Using method, investigated water samples from 10 pools found 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ) the...

Therapeutic uses of DNA functionalized gold nanoparticles (DNA-AuNPs) have shown great potential and exciting opportunities for disease diagnostics treatment. Maintaining stable conjugation between oligonucleotides under thermally stressed conditions is one the critical aspects any practical applications. We systematically studied thermal stability DNA-AuNPs as affected by organosulfur anchor groups packing densities. Using a fluorescence assay to determine kinetics releasing molecules from...

We describe a sensitive and specific sandwich assay for human α-thrombin. The takes advantage of binding two affinity aptamers increased specificity, gold nanoparticles signal amplification, magnetic beads fast separation, inductively coupled plasma mass spectrometry ultrasensitive detection. Other proteins, such as immunoglobulin G, serum albumin, transferrin, fibrinogen, lysozyme did not show interference with the detection limit α-thrombin was low 0.5 fmol, corresponding to 10 pM thrombin...

Halobenzoquinones (HBQs) are a structurally diverse class of water disinfection byproducts. Here, we report systematic study on the effects isomeric structure and type number halogen substitutions HBQs their cytotoxicity, formation reactive oxygen species (ROS), genotoxicity. Dynamic responses IC50 histograms were obtained using real-time cell analysis, clearly ranking cytotoxicity in Chinese hamster ovary (CHO-K1) cells. Strong shown with 2,5-HBQ isomers inducing greater than corresponding...