"Microlaboratory" measures the level of sugar in one drop of sweat
Accurate and timely measurement of blood glucose is a necessary part of medical diagnosis. In particular, insulin deficiency and excess blood sugar are the two main causes of diabetes, and both can be identified by examining glucose levels. At the present moment, based on fiber-optic technologies and microhydrodynamics, the researchers have developed an inexpensive and extremely sensitive device, which is a kind of “micro-laboratory” that has the ability to determine the level of glucose by just one drop of sweat.
On the original technology - under the cut.
A team from Hong Kong Polytechnic University and Zhejiang University is developing a device for early diagnosis and prevention of diabetes.
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The technology used relates to a new field, called “optohydrodynamics,” combining photon perception (using the properties of light to detect the presence of certain chemicals) and microhydrodynamics (studying the behavior of flow of small volumes of liquid through microchannels).
The uniqueness of the new device is that, according to an article in Biomedical Optics Express, it uses fiber to detect glucose. The introduction of this type of sensor in a micro-hydrodynamic chip makes the device not only extremely sensitive, but also convenient for everyday wear, and, most importantly, inexpensive.
A. Ping Zhang, associate professor of electrical engineering at Hong Kong Polytechnic University, talks about the photon approach as one of the most promising technologies of ultra-precise perception.
When combining photonics with small-sized platforms (micro-hydrodynamic chips), we get a compact analytical micro-laboratory that promptly provides accurate data.
Other researchers have attempted to introduce electrochemical sensors that detect the presence of glucose into microhydrodynamic channels in order to obtain compact and inexpensive chips, but have encountered such problems as electromagnetic interference in electrochemical sensors. That is why the team chose a fiber that is not exposed to this effect.
A fiber biosensor detects even extremely low amounts of glucose in solution.
In his article, Zhang and colleagues describe the technique by which they combined a fiber optic biosensor with a micro-hydrodynamic chip to create an opto-hydrodynamic device for ultra-precise glucose measurement, not subject to electromagnetic interference. The optical sensor created by them is extremely sensitive to changes in the refractive index of the medium surrounding it. To transform this device into a glucose sensor, the scientists used a glucose oxidase film as a detector material; The choice of this material was due to its reaction to glucose in solution.
To maintain the sensing layer and to improve the quality and stability of the signal, the team also applied a layer of polyethyleneimine (PEI) and a layer of polyacrylic acid (PAA) directly onto the sensor. Zhang explains that a PEI / PAA bilayer film " controls the oxidation of glucose on the glucose oxidase catalyst and reacts to this oxidation by swelling or contracting ."
Zhang says that after conducting a series of tests, the team came to the conclusion that "the fiber optic sensor is very sensitive by itself and can detect extremely low concentrations of glucose oxidase, on the order of 1 nmol (molarity 10 minus ninth), " but after they implemented its micro-hydrodynamic chip, the sensor performance " has increased markedly ."
Expansion of the measurement limits was not the only improvement in the sensor's performance: the measurement time significantly decreased, according to the researchers, " it decreased from 6 minutes to 70 seconds ."
The device detects glucose in solution - so it can be used to measure glucose from the slightest drop of sweat.
" This fact makes this technology ideal for early diagnosis of diabetes by measuring the level of glucose in sweat ." - prof. And Ping Zhang
In the future, the team expects to develop a range of multi-functional “micro-laboratories” for use in research and development in various fields, from biomedical diagnostics to environmental monitoring, as well as in the development of medicines.
On the original technology - under the cut.
A team from Hong Kong Polytechnic University and Zhejiang University is developing a device for early diagnosis and prevention of diabetes.
')
The technology used relates to a new field, called “optohydrodynamics,” combining photon perception (using the properties of light to detect the presence of certain chemicals) and microhydrodynamics (studying the behavior of flow of small volumes of liquid through microchannels).
The uniqueness of the new device is that, according to an article in Biomedical Optics Express, it uses fiber to detect glucose. The introduction of this type of sensor in a micro-hydrodynamic chip makes the device not only extremely sensitive, but also convenient for everyday wear, and, most importantly, inexpensive.
A. Ping Zhang, associate professor of electrical engineering at Hong Kong Polytechnic University, talks about the photon approach as one of the most promising technologies of ultra-precise perception.
When combining photonics with small-sized platforms (micro-hydrodynamic chips), we get a compact analytical micro-laboratory that promptly provides accurate data.
Other researchers have attempted to introduce electrochemical sensors that detect the presence of glucose into microhydrodynamic channels in order to obtain compact and inexpensive chips, but have encountered such problems as electromagnetic interference in electrochemical sensors. That is why the team chose a fiber that is not exposed to this effect.
A fiber biosensor detects even extremely low amounts of glucose in solution.
In his article, Zhang and colleagues describe the technique by which they combined a fiber optic biosensor with a micro-hydrodynamic chip to create an opto-hydrodynamic device for ultra-precise glucose measurement, not subject to electromagnetic interference. The optical sensor created by them is extremely sensitive to changes in the refractive index of the medium surrounding it. To transform this device into a glucose sensor, the scientists used a glucose oxidase film as a detector material; The choice of this material was due to its reaction to glucose in solution.
To maintain the sensing layer and to improve the quality and stability of the signal, the team also applied a layer of polyethyleneimine (PEI) and a layer of polyacrylic acid (PAA) directly onto the sensor. Zhang explains that a PEI / PAA bilayer film " controls the oxidation of glucose on the glucose oxidase catalyst and reacts to this oxidation by swelling or contracting ."
Zhang says that after conducting a series of tests, the team came to the conclusion that "the fiber optic sensor is very sensitive by itself and can detect extremely low concentrations of glucose oxidase, on the order of 1 nmol (molarity 10 minus ninth), " but after they implemented its micro-hydrodynamic chip, the sensor performance " has increased markedly ."
Expansion of the measurement limits was not the only improvement in the sensor's performance: the measurement time significantly decreased, according to the researchers, " it decreased from 6 minutes to 70 seconds ."
The device detects glucose in solution - so it can be used to measure glucose from the slightest drop of sweat.
" This fact makes this technology ideal for early diagnosis of diabetes by measuring the level of glucose in sweat ." - prof. And Ping Zhang
In the future, the team expects to develop a range of multi-functional “micro-laboratories” for use in research and development in various fields, from biomedical diagnostics to environmental monitoring, as well as in the development of medicines.
Source: https://habr.com/ru/post/394177/
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