A5056332400- Advanced biosensing and bioanalysis techniques
- Electrochemical Analysis and Applications
- Analytical Chemistry and Sensors
- Molecular Junctions and Nanostructures
- Biosensors and Analytical Detection
- Fluorine in Organic Chemistry
- Catalytic Cross-Coupling Reactions
- Electrochemical sensors and biosensors
- Neuroscience and Neuropharmacology Research
- Receptor Mechanisms and Signaling
- DNA and Nucleic Acid Chemistry
- Polymer Surface Interaction Studies
- Advanced Chemical Sensor Technologies
- Organoboron and organosilicon chemistry
- Microfluidic and Capillary Electrophoresis Applications
- Catalytic C–H Functionalization Methods
- SARS-CoV-2 detection and testing
- Quantum Dots Synthesis And Properties
- Advanced Biosensing Techniques and Applications
University of California, Santa Barbara
2021-2024
University of British Columbia
2014-2020
The ability to monitor drugs, metabolites, hormones, and other biomarkers in situ the body would greatly advance both clinical practice biomedical research. To this end, we are developing electrochemical aptamer-based (EAB) sensors, a platform technology able perform real-time, vivo monitoring of specific molecules irrespective their chemical or enzymatic reactivity. An important obstacle deployment EAB sensors challenging environments found living is signal drift, whereby sensor decreases...
Abstract Electrochemical aptamer-based (EAB) sensors support the real-time, high frequency measurement of pharmaceuticals and metabolites in-situ in living body, rendering them a potentially powerful technology for both research clinical applications. Here we explore quantification using EAB sensors, examining impact media selection temperature on performance. Using freshly-collected, undiluted whole blood at body as our calibration conditions, demonstrate accuracy better than ± 10% test bed...
Knowledge of drug concentrations in the brains behaving subjects remains constrained on a number dimensions, including poor temporal resolution and lack real-time data. Here, however, we demonstrate ability electrochemical aptamer-based sensors to support seconds-resolved, measurements freely moving rats. Specifically, using such sensors, achieve <4 μM limits detection 10-s measurement procaine rats, permitting determination pharmacokinetics concentration-behavior relations with high...
EAB sensors stored at −20 °C for least six months perform comparably to freshly fabricated sensors.
Abstract We report herein a general catalytic method for Csp 2 Csp 3 bond formation through CF activation. The process uses an inexpensive nickel complex with either diorganozinc or alkylzinc halide reagents, including those β‐hydrogen atoms. A variety of fluorine substitution patterns and functional groups can be readily incorporated. Sequential reactions involving different precatalysts coupling partners permit the synthesis densely functionalized fluorinated building blocks.
Electrochemical aptamer-based (EAB) sensors are capable of measuring the concentrations specific molecules in vivo, real time, and with a few-second time resolution. For their signal transduction mechanism, these utilize binding-induced conformational change target-recognizing, redox-reporter-modified aptamer to alter rate electron transfer between reporter supporting electrode. While variety voltammetric techniques have been used monitor this kinetics, they suffer from various drawbacks,...
Electrochemical aptamer-based sensors support the high-frequency, real-time monitoring of molecules-of-interest in vivo. Achieving this requires methods for correcting sensor drift seen during vivo placements. While correction ensures EAB measurements remain accurate, as progresses it reduces signal-to-noise ratio and precision. Here, we show that enzymatic cleavage sensor's target-recognizing DNA aptamer is a major source signal loss. To demonstrate this, deployed tobramycin-detecting...
Electrochemical aptamer-based (EAB) sensors represent the first molecular measurement technology that is both (1) independent of chemical reactivity target, and thus generalizable to many targets (2) able function in an accurate, drift-corrected manner situ living body. Signaling EAB generated when electrode-bound aptamer binds its target ligand, altering rate electron transfer from attached redox reporter producing easily detectable change peak current sensor interrogated using square wave...
Electrochemical aptamer-based sensors are the first molecular monitoring technology that support real-time measurements in living body. Electrode placement plays a key role performance of these when they deployed for intravenous measurements.
Abstract Electrochemical aptamer‐based sensors support the high‐frequency, real‐time monitoring of molecules‐of‐interest in vivo. Achieving this requires methods for correcting sensor drift seen during vivo placements. While correction ensures EAB measurements remain accurate, as progresses it reduces signal‐to‐noise ratio and precision. Here, we show that enzymatic cleavage sensor's target‐recognizing DNA aptamer is a major source signal loss. To demonstrate this, deployed...
The availability of high-frequency, real-time measurements the concentrations specific metabolites in cell culture systems will enable a deeper understanding cellular metabolism and facilitate application good laboratory practice standards protocols. However, currently available approaches to this end either are constrained single-time-point single-parameter or limited range detectable analytes. Electrochemical aptamer-based (EAB) biosensors have demonstrated utility monitoring analytes
Electrochemical aptamer-based sensors support real-time, in vivo molecular measurements. Here we compare the relative merits of square-wave, alternating current, and differential pulse voltammetry interrogation such sensors.
DNA self-assembled monolayers (SAMs) were prepared using potential-assisted deposition on clean gold single-crystal bead electrodes under a number of conditions (constant or square-wave potential perturbations in TRIS phosphate immobilization buffers with and without Cl–). The local environment around the fluorophore-labeled tethered to electrode surface was characterized situ fluorescence microscopy during electrochemical measurements as function underlying crystallography....
The preparation of DNA self-assembled monolayers (SAMs) on single-crystal gold bead electrodes using an applied potential is evaluated with in situ electrochemical fluorescence microscopy. Applying a constant deposition or square-wave perturbation during the formation SAMs compared for two different modification methods: SAM clean surface followed by alkythiol backfilling (as typically done literature) via thiol-exchange alkylthiol-modified surface. prepared from chloride-containing buffer...
Manipulating the composition of a mixed alkylthiol self-assembled monolayer (SAM) modified gold surface using both electrochemical and electroless methods is demonstrated. Through use fluorophore labeled thiolated DNA in situ fluorescence microscopy with single crystal bead electrode, procedure was developed to study quantify selective desorption an alkylthiolate SAM. This method enabled self-consistent measurement removal SAM from 111 compared 100 region at various potentials. A 20-fold...
The ability to measure drug, metabolite and biomarker levels in the living body, real time, at high frequency would revolutionize our understand diagnose disease personalize guide its treatment. To this end, Plaxco group has been developing electrochemical aptamer-based (EAB) sensors, a platform technology able molecules body independently of chemical or enzymatic reactivity targets. This enabled development sensors capable measuring both drugs (e.g., antibiotics, chemotherapeutics,...
We show that using fast Fourier transform electrochemical impedance spectroscopy (FFT-EIS) to interrogate aptamer-based biosensors leads improved (here better than 2 s) time resolution and calibration-free operation, even when such sensors are deployed in vivo. Because this approach uses the heterogeneous electron transfer rate constant as a means of monitoring target concentration, rather absolute current, it is independent both sensor-to-sensor fabrication variation drift arising due...
Abstract A new route to generate alkyl substituted aryl fluorides, such as (III), (V), (VIII) and (XI) through Ni‐catalyzed Negishi cross‐coupling reactions is described.
Typically, DNA SAMs used for electrochemical based sensing are prepared without controlling the gold electrode potential[1]. Applying a potential during deposition enables control over coverage and organization[2-4]. These characteristics determined by composition of immobilization buffer, immersion time, concentration, extent backfilling with small alkylthiol whether occurs on bare or alkythiol surface[3-4]. Few studies have explored influence underlying surface crystallography. Here, we...