A multilayered PDMS based microtas for high-sensitivity insulin detection (original) (raw)
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Insulin detection based on a PDMS microfluidic system
2010 IEEE International Conference on Nano/Molecular Medicine and Engineering, 2010
An integrated polydimethysiloxane (PDMS) microfluidic system which is composed of two pneumatic micropumps and one micromixer is developed for high-accuracy detection of insulin. The detection method is based on coupling the highly specific technique of 'double-antibody sandwich immunoassay' with the sensitive chemiluminescence of Luminol-Hydrogen Peroxide (H 2 O 2). The immune reactions and other related processes are carried out in the microfluidic system semi automatically. Sample transportation in the microfluidic system is accomplished by two pneumatic PDMS micropumps. Chemiluminescent measurement is conducted in a separate PDMS micromixer using a double-channel syringe pump to inject reagents. Light emitting from this mixer is detected by a highly sensitive photometer when the chemiluminescent regents flow through the mixer chamber. The results indicate that at an actuation pressure of 10psi, a mixer actuation frequency of 5Hz, and an injecting flow rate of 0.5 ml/min, the detection limit of the microfluidic system for insulin is about 10-10 M.
Investigation of a PDMS Based Micromixer for Heterogeneous Immunoassays of Insulin
Proceedings of the 2010 5th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, 2010
An experimental study was carried out to evaluate the performance of a polydimethylsiloxane (PDMS) based micromixer for heterogeneous immunoassays of insulin. The detection method is based on coupling the highly specific double-antibody sandwich immunoassay with the sensitive chemiluminescence of the Luminol-Hydrogen Peroxide reaction. Both the immune and chemiluminescence reactions are conducted in the micromixer, and the resultant light emission is detected by a highly sensitive photometer. The behavior of the luminol based chemiluminescence is parabolic with respect to time, and the maximum light intensity is used here to represent the output of the reaction. The current results indicate that at an actuation pressure of 15psi, an actuation frequency of 30Hz leads to the best reaction result. At these operating conditions, the detection limit of insulin is about 10-14 mol/L while the total reaction time of the insulin immunoassay in the micromixer is less than 5 minutes.
Development of a Microsphere-Based System to Facilitate Real-Time Insulin Monitoring
Journal of diabetes science and technology, 2015
The speed of insulin absorption after subcutaneous delivery is highly variable. Incorrect assumptions about insulin pharmacokinetics compromise effective glycemic regulation. Our ultimate goal is to develop a system to monitor insulin levels in vivo continuously, allowing pharmacokinetic parameters to be calculated in real time. We hypothesize that a bead-based detection system can be run on a flow-through microfluidic platform to measure insulin in subcutaneous fluid sampled via microdialysis. As a first step in development, we focused on microsphere-based measurement of insulin. Polystyrene microspheres coated with an anti-insulin monoclonal antibody were exposed to insulin-containing solutions, and after addition of a fluorescently labeled anti-insulin monoclonal antibody with a distinct epitope, bead-associated fluorescence was detected by fluorescence microscopy in 96-well plates or in a flow-through, microfluidic platform. The bead detection system in plates had a linear range...
A micro-bioimpedance meter for monitoring insulin bioavailability in personalized diabetes therapy
Scientific Reports
An on-chip transducer, for monitoring noninvasively the insulin bio-availability in real time after administration in clinical diabetology, is proposed. The bioavailability is assessed as insulin decrease in situ after administration by means of local impedance measurement. Inter-and-intra individual reproducibility is enhanced by a personalized model, specific for the subject, identified and validated during each insulin administration. Such a real-time noninvasive bioavailability measurement allows to increase the accuracy of insulin bolus administration, by attenuating drawbacks of glycemic swings significantly. In the first part of this paper, the concept, the architecture, and the operation of the transducer, as well as details about its prototype, are illustrated. Then, the metrological characterization and validation are reported in laboratory, in vitro on eggplants, ex vivo on pig abdominal non-perfused muscle, and in vivo on a human subject, using injection as a reference s...
BioMEMS device with integrated microdialysis probe and biosensor array
Biosensors and Bioelectronics, 2002
The fabrication of a microdevice for continuous sampling and on-line monitoring of glucose is described. The device comprised a microdialysis sampling system integrated on the flow through channel of a microfabricated enzyme sensor. The sensor was produced by thin film technology and was assembled to a printed circuit board (PCB) that provided the means for both electrical and fluidic connections. A polyacrilonitrile fibre, with a cutoff of 50 kDa, was used in the fabrication of the sampling probe. The performance of the device was evaluated in-vitro. High sampling efficiency of the microdialysis probe was achieved by appropriate selection of the perfusion fluid flow rate. Response times varying from 1.5 to 3.0 min were determined for flow rates ranging between 1 and 0.2 ml/ min. The linear response range was up to 30 mM glucose and interference from other electroactive substances was almost negligible. The device showed excellent stability under continuous operation for at least 5 days and sensitivity variation less than 3% over a period of 15 days.
Biosensors and Bioelectronics, 2003
The simultaneous on-line determination of glucose and lactate using a microdevice that consisted of a dialysis sampling system incorporated to the flow-through cell of a microfabricated biosensor array is presented. The fluidic connections between the different device's components were realized by subsequent processing of stacked dry resist layers on a plastic support that provided also the means for electric connections. The performance of the device was evaluated in vitro. The cross-talk effect on the downstream sensor was investigated and found to be negligible. Recoveries of over 95% for both analytes were achieved when flow rates of the perfusion fluid 5/0.5 ml/min were used. At this flow rate, the response time of the device was 2.4 min, which is acceptable for on-line analysis. The linear response concentration range extended up to 30 mM for glucose and 15 mM for lactate. Interference from electroactive species such as ascorbic acid, 2-acetamidophenol and uric acid, was minimal (less than 5% increase in biosensors signal for all substances tested). In addition, the device presented long-term run stability both in buffer and serum samples.
Industrialized Functional Test for Insulin Micropumps
Procedia Engineering, 2011
We report on original industrialized functional testing methods for insulin micropumps. A specific Design-For-Test associated with the analysis of the integrated pressure sensor signal, during a specific actuation profile, allows a complete characterization of the pump functionality in few seconds. All critical failures due to fabrication and assembly create clear and specific deviations from nominal signal. The pressure sensor sensitivity coupled to the high compression ratio and the small dead volume of the micropump lead to a leak detection sensitivity of only few nl/h for water or insulin at 37°C.
A microflow amperometric glucose biosensor
Biosensors and Bioelectronics, 1997
We investigate a small glucose sensor that uses a flow-through enzyme bed and reaction endpoint approach that seems particularly suited to microdialysis-type subcutaneous or intravascular glucose sensors. The particular configuration has the advantage of relative insensitivity to blood oxygen changes and also to factors which affect enzyme activity compared to conventional polarographic type glucose sensors. We evaluate the placement of a microdialysis fiber into a near-surface blood vessel in the dog model as a means of blood glucose sampling and to determine the effects of protein deposition. We observe a progressive decline in intravascular membrane fiber transport that must be considered in sensor design.
Microprocessor-based insulin delivery device with amperometric glucose sensing
2006 International Conference on Industrial and Information Systems, 2006
Chee, Fred, Fernando, Tyrone L. and Trinh, Hieu M. 2006, Microprocessorbased insulin delivery device with amperometric glucose sensing, in ETFA Abstract This paper details the design ofa closed-loop insulin delivery device, consisting of a glucose sensing circuit, and a basic microprocessor-based syringe pump. The glucose sensing circuit contains the required components to interface with CGMS's glucose sensor assembly, while the syringe pump design uses microprocessor to allow flexible control over the pump driver Instrumentation developed in this paper provides a ready reference to other researchers on the construction of a closed-loop insulin delivery apparatus with amperometric glucose sensor