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3D Printed Microfluidic Device with Integrated Biosensors for Online Analysis of Subcutaneous Human Microdialysate.

Gowers SA, Curto VF, Seneci CA, Wang C, Anastasova S, Vadgama P, Yang GZ, Boutelle MG - Anal. Chem. (2015)

Bottom Line: A soft compressible 3D printed elastomer at the base of the holder ensures a good seal with the microfluidic chip.Optimization of the channel size significantly improves the response time of the sensor.As a proof-of-concept study, our microfluidic device was coupled to lab-built wireless potentiostats and used to monitor real-time subcutaneous glucose and lactate levels in cyclists undergoing a training regime.

View Article: PubMed Central - PubMed

Affiliation: §School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom.

ABSTRACT
This work presents the design, fabrication, and characterization of a robust 3D printed microfluidic analysis system that integrates with FDA-approved clinical microdialysis probes for continuous monitoring of human tissue metabolite levels. The microfluidic device incorporates removable needle type integrated biosensors for glucose and lactate, which are optimized for high tissue concentrations, housed in novel 3D printed electrode holders. A soft compressible 3D printed elastomer at the base of the holder ensures a good seal with the microfluidic chip. Optimization of the channel size significantly improves the response time of the sensor. As a proof-of-concept study, our microfluidic device was coupled to lab-built wireless potentiostats and used to monitor real-time subcutaneous glucose and lactate levels in cyclists undergoing a training regime.

No MeSH data available.


A. Standardmicrodialysis setup for discrete sampling. The probe(a) is perfused at a fixed low flow rate, and dialysateis collected into a microvial (b) at the probe outlet. Right: shows the microvial when connected to the probe outletholder. B. Photograph of combined needle electrode based on a 27Ghypodermic needle and schematic cross-section of the needle tip, showingthe layers that make up the biosensor: (i) m-PD exclusionlayer, (ii) substrate oxidase (SOx) entrapped ina hydrogel, and (iii) diffusion limiting polyurethaneouter film. C. Exploded view of custom-made microfluidic device forcontinuous monitoring of dialysate, showing the multicomponent system.The microfluidic chip (e) connects to the probe outletholder (c) in place of a microvial. The outlet holderneedle enters the microvial rubber insert (d) atthe inlet of the microfluidic chip. Glucose and lactate needle biosensors(f) are housed in custom-made electrode holders (g) that screw into the microfluidic chip, placing the biosensorsin the middle of the microfluidic channel and providing a good sealbetween the holder and the microfluidic device. (h) shows a photograph of an electrode holder containing a needle biosensor.The black part at the base of the holder is made of soft, compressibleplastic to ensure the holder makes a good seal with the microfluidicchip. D. The L-shaped design provides a tidy and compact overall system.
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fig1: A. Standardmicrodialysis setup for discrete sampling. The probe(a) is perfused at a fixed low flow rate, and dialysateis collected into a microvial (b) at the probe outlet. Right: shows the microvial when connected to the probe outletholder. B. Photograph of combined needle electrode based on a 27Ghypodermic needle and schematic cross-section of the needle tip, showingthe layers that make up the biosensor: (i) m-PD exclusionlayer, (ii) substrate oxidase (SOx) entrapped ina hydrogel, and (iii) diffusion limiting polyurethaneouter film. C. Exploded view of custom-made microfluidic device forcontinuous monitoring of dialysate, showing the multicomponent system.The microfluidic chip (e) connects to the probe outletholder (c) in place of a microvial. The outlet holderneedle enters the microvial rubber insert (d) atthe inlet of the microfluidic chip. Glucose and lactate needle biosensors(f) are housed in custom-made electrode holders (g) that screw into the microfluidic chip, placing the biosensorsin the middle of the microfluidic channel and providing a good sealbetween the holder and the microfluidic device. (h) shows a photograph of an electrode holder containing a needle biosensor.The black part at the base of the holder is made of soft, compressibleplastic to ensure the holder makes a good seal with the microfluidicchip. D. The L-shaped design provides a tidy and compact overall system.

Mentions: All biosensors were controlledusing in-house potentiostats and a PowerLab 8/35, controlled by LabChartPro (ADInstruments). Glucose and lactate biosensors were fabricatedin several layers, as shown in Figure 1-B. Layer i: The working electrode was first coated with polym-phenylenediamine (m-PD) using electropolymerization, to screen outpotential interferences. Briefly, the combined needle electrode wasplaced in a 100 mM solution of m-phenylenediamine in 0.01 M PBS atpH 7.4. The potential was held at 0 V for 20 s, 0.7 V for 20 min forelectropolymerization to occur, and then 0 V for 5 min. The electrodewas gently rinsed with deionized water, and cyclic voltammetry wasused to verify that the working electrode had been successfully coated. Layer ii: After successful electropolymerization of thescreening layer, the electrodes were dipped into the enzyme solution(60 mg/mL LOx or GOx, 30 mg/mL bovine serum albumin, 60 mg/mL poly(ethyleneglycol) diglycidyl ether, and 2% v/v glycerol in0.01 M PBS, adapted from the method described by Vasylieva et al.37,38). The needles were placed in an oven at 55 °C for 2 h. Layer iii: Following enzyme immobilization, biosensors werealso coated with a polyurethane film in order to extend their dynamicrange to include the higher lactate levels possible in exercisingtissue and to minimize the effect of any flow variations, which couldoccur in a flow-cell, on biosensor response.


3D Printed Microfluidic Device with Integrated Biosensors for Online Analysis of Subcutaneous Human Microdialysate.

Gowers SA, Curto VF, Seneci CA, Wang C, Anastasova S, Vadgama P, Yang GZ, Boutelle MG - Anal. Chem. (2015)

A. Standardmicrodialysis setup for discrete sampling. The probe(a) is perfused at a fixed low flow rate, and dialysateis collected into a microvial (b) at the probe outlet. Right: shows the microvial when connected to the probe outletholder. B. Photograph of combined needle electrode based on a 27Ghypodermic needle and schematic cross-section of the needle tip, showingthe layers that make up the biosensor: (i) m-PD exclusionlayer, (ii) substrate oxidase (SOx) entrapped ina hydrogel, and (iii) diffusion limiting polyurethaneouter film. C. Exploded view of custom-made microfluidic device forcontinuous monitoring of dialysate, showing the multicomponent system.The microfluidic chip (e) connects to the probe outletholder (c) in place of a microvial. The outlet holderneedle enters the microvial rubber insert (d) atthe inlet of the microfluidic chip. Glucose and lactate needle biosensors(f) are housed in custom-made electrode holders (g) that screw into the microfluidic chip, placing the biosensorsin the middle of the microfluidic channel and providing a good sealbetween the holder and the microfluidic device. (h) shows a photograph of an electrode holder containing a needle biosensor.The black part at the base of the holder is made of soft, compressibleplastic to ensure the holder makes a good seal with the microfluidicchip. D. The L-shaped design provides a tidy and compact overall system.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526885&req=5

fig1: A. Standardmicrodialysis setup for discrete sampling. The probe(a) is perfused at a fixed low flow rate, and dialysateis collected into a microvial (b) at the probe outlet. Right: shows the microvial when connected to the probe outletholder. B. Photograph of combined needle electrode based on a 27Ghypodermic needle and schematic cross-section of the needle tip, showingthe layers that make up the biosensor: (i) m-PD exclusionlayer, (ii) substrate oxidase (SOx) entrapped ina hydrogel, and (iii) diffusion limiting polyurethaneouter film. C. Exploded view of custom-made microfluidic device forcontinuous monitoring of dialysate, showing the multicomponent system.The microfluidic chip (e) connects to the probe outletholder (c) in place of a microvial. The outlet holderneedle enters the microvial rubber insert (d) atthe inlet of the microfluidic chip. Glucose and lactate needle biosensors(f) are housed in custom-made electrode holders (g) that screw into the microfluidic chip, placing the biosensorsin the middle of the microfluidic channel and providing a good sealbetween the holder and the microfluidic device. (h) shows a photograph of an electrode holder containing a needle biosensor.The black part at the base of the holder is made of soft, compressibleplastic to ensure the holder makes a good seal with the microfluidicchip. D. The L-shaped design provides a tidy and compact overall system.
Mentions: All biosensors were controlledusing in-house potentiostats and a PowerLab 8/35, controlled by LabChartPro (ADInstruments). Glucose and lactate biosensors were fabricatedin several layers, as shown in Figure 1-B. Layer i: The working electrode was first coated with polym-phenylenediamine (m-PD) using electropolymerization, to screen outpotential interferences. Briefly, the combined needle electrode wasplaced in a 100 mM solution of m-phenylenediamine in 0.01 M PBS atpH 7.4. The potential was held at 0 V for 20 s, 0.7 V for 20 min forelectropolymerization to occur, and then 0 V for 5 min. The electrodewas gently rinsed with deionized water, and cyclic voltammetry wasused to verify that the working electrode had been successfully coated. Layer ii: After successful electropolymerization of thescreening layer, the electrodes were dipped into the enzyme solution(60 mg/mL LOx or GOx, 30 mg/mL bovine serum albumin, 60 mg/mL poly(ethyleneglycol) diglycidyl ether, and 2% v/v glycerol in0.01 M PBS, adapted from the method described by Vasylieva et al.37,38). The needles were placed in an oven at 55 °C for 2 h. Layer iii: Following enzyme immobilization, biosensors werealso coated with a polyurethane film in order to extend their dynamicrange to include the higher lactate levels possible in exercisingtissue and to minimize the effect of any flow variations, which couldoccur in a flow-cell, on biosensor response.

Bottom Line: A soft compressible 3D printed elastomer at the base of the holder ensures a good seal with the microfluidic chip.Optimization of the channel size significantly improves the response time of the sensor.As a proof-of-concept study, our microfluidic device was coupled to lab-built wireless potentiostats and used to monitor real-time subcutaneous glucose and lactate levels in cyclists undergoing a training regime.

View Article: PubMed Central - PubMed

Affiliation: §School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom.

ABSTRACT
This work presents the design, fabrication, and characterization of a robust 3D printed microfluidic analysis system that integrates with FDA-approved clinical microdialysis probes for continuous monitoring of human tissue metabolite levels. The microfluidic device incorporates removable needle type integrated biosensors for glucose and lactate, which are optimized for high tissue concentrations, housed in novel 3D printed electrode holders. A soft compressible 3D printed elastomer at the base of the holder ensures a good seal with the microfluidic chip. Optimization of the channel size significantly improves the response time of the sensor. As a proof-of-concept study, our microfluidic device was coupled to lab-built wireless potentiostats and used to monitor real-time subcutaneous glucose and lactate levels in cyclists undergoing a training regime.

No MeSH data available.