In-flow electrochemical detection of chemicals in droplets with pyrolysed photoresist electrodes: application as a module for quantification of microsampled dopamine

Leroy, Albert; Teixidor, Joan; Bertsch, Arnaud; Renaud, Philippe

doi:10.1039/d1lc00116g

Cited by 7 publications

(5 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We and others have previously shown that it is possible to collect from sampling probes into nanoliter droplets, corresponding to seconds of fraction collection, that are separated by an immiscible carrier fluid. [19][20][21][22][23][24][25][26][27][28][29] Droplet microfluidics facilitates manipulation of the small samples collected and interface to analytical methods with highthroughput and mass sensitivity like chip electrophoresis, 30,31 electrospray ionization-tandem mass spectrometry (ESI-MS/ MS), 32,33 inductively coupled plasma-mass spectrometry (ICP-MS), 34 electrochemical sensors, 22 and luminescence assays 24 to achieve temporal resolution of seconds.…”

Section: Introductionmentioning

confidence: 99%

Microdialysis coupled with droplet microfluidics and mass spectrometry for determination of neurotransmitters in vivo with high temporal resolution

Wells,

Bain,

Valenta

et al. 2024

Analyst

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Microdialysis coupled with droplet microfluidics and mass spectrometry for determination of neurotransmitters in vivo with high temporal resolution

Wells,

Bain,

Valenta

et al. 2024

Analyst

View full text Add to dashboard Cite

show abstract

“…Droplet generation using microfluidics is a well-known, established technique and has many applications in chemical and biological sciences [ 16 ]. Several new and improved methods have been reported to generate droplets and have demonstrated applications in developing different biological assays [ 17 , 18 , 19 ]. A microfluidics-based strategy was combined with a DNAzyme sensor to detect E. coli (E. coli K12) from unprocessed blood samples [ 20 ].…”

Section: Introductionmentioning

confidence: 99%

Digital E. coli Counter: A Microfluidics and Computer Vision-Based DNAzyme Method for the Isolation and Specific Detection of E. coli from Water Samples

et al. 2022

View full text Add to dashboard Cite

Biological water contamination detection-based assays are essential to test water quality; however, these assays are prone to false-positive results and inaccuracies, are time-consuming, and use complicated procedures to test large water samples. Herein, we show a simple detection and counting method for E. coli in the water samples involving a combination of DNAzyme sensor, microfluidics, and computer vision strategies. We first isolated E. coli into individual droplets containing a DNAzyme mixture using droplet microfluidics. Upon bacterial cell lysis by heating, the DNAzyme mixture reacted with a particular substrate present in the crude intracellular material (CIM) of E. coli. This event triggers the dissociation of the fluorophore-quencher pair present in the DNAzyme mixture leading to a fluorescence signal, indicating the presence of E. coli in the droplets. We developed an algorithm using computer vision to analyze the fluorescent droplets containing E. coli in the presence of non-fluorescent droplets. The algorithm can detect and count fluorescent droplets representing the number of E. coli present in the sample. Finally, we show that the developed method is highly specific to detect and count E. coli in the presence of other bacteria present in the water sample.

show abstract

“…This benefitted from the rich literature of droplet microfluidics (e.g., droplet generation 28 , picoinjection 29 , phase extraction [30][31][32] , etc.). These solutions, which were extensively covered in recent reviews [33][34][35][36] , comprise in-flow electrochemical chips 37,38 , fluorescent assays 23,39,40 and include many developments of electrophoretic 30,41 and mass spectrometry methods 26,[42][43][44][45][46][47][48] .…”

Section: Introductionmentioning

confidence: 99%

On demand nanoliter sampling probe for collection of brain fluid

Teixidor

Novello

Ortiz

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Continuous fluidic sampling systems allow collection of brain biomarkers in vivo. Here, we propose a new sampling paradigm, Droplet on Demand (DoD), implemented in a microfabricated neural probe. It allows sampling droplets loaded with molecules from the brain extracellular fluid punctually, without the long transient equilibration periods typical of continuous methods. It uses an accurate fluidic sequence and correct operation is verified by the embedded electrodes. As a proof of concept, we demonstrated the application of this novel approach in vitro and in vivo, to collect glucose in the brain of mice, with a temporal resolution of 1-2 minutes and without transient regime. Absolute quantification of the glucose level in the samples was performed by direct infusion nanoelectrospray ionization Fourier transform mass spectrometry (nanoESI-FTMS). By adjusting the diffusion time and the perfusion volume of DoD, the fraction of molecules recovered in the samples can be tuned to mirror the tissue concentration at accurate points in time. This makes quantification of biomarkers in the brain possible within acute experiments of only 20 to 120 minutes. DoD provides a complementary tool to continuous microdialysis and push-pull sampling probes. The advances allowed by DoD will benefit quantitative molecular studies in the brain, namely for molecules involved in volume transmission or for protein aggregates that form in neurodegenerative diseases over long periods.

show abstract

In-flow electrochemical detection of chemicals in droplets with pyrolysed photoresist electrodes: application as a module for quantification of microsampled dopamine

Abstract: The electrochemical quantification of analytes in droplets of PBS separated by a fluorinated phase was investigated. PDMS-fused silica chips with pyrolysed photoresist electrodes were prepared using a simple fabrication technique...

Cited by 7 publications

References 58 publications

Microdialysis coupled with droplet microfluidics and mass spectrometry for determination of neurotransmitters in vivo with high temporal resolution

Microdialysis coupled with droplet microfluidics and mass spectrometry for determination of neurotransmitters in vivo with high temporal resolution

Digital E. coli Counter: A Microfluidics and Computer Vision-Based DNAzyme Method for the Isolation and Specific Detection of E. coli from Water Samples

On demand nanoliter sampling probe for collection of brain fluid

Contact Info

Product

Resources

About