Microfluidic platforms have altered medical diagnostics in current years. Rather than sending blood or urine samples off to a laboratory for analysis, doctors can experiment a singular drop of a patient’s urine or blood for various ailments at the point-of-care without the requirement for expensive instruments. Before the sample can be analysed, however, doctors require inserting particular ailment – detecting biomolecules into the microfluidic platform.
While performing such, it has to be ensured that such biomolecules are well-bound to the inside of the device to protect them from being flushed out by the incoming sample. As such preparatory step can be time-consuming; it would be beneficial if microfluidic platform could come pre-prepared with particular biomolecules sealed within. But, such sealing procedures need exposure of the device elements to high energy or ‘ionized gas’ and whether biomolecules can survive such rigid process is unknown.
For answering this question, the scientists at the Okinawa Institute of Technology and Science Graduate University (OIST) have prepared a new sensor that identifies biomolecules more precisely than ever before. Such sensor was utilized to illustrate that biomolecules can be successfully sealed within microfluidic devices.
The results deliver profound implications for healthcare diagnostics and open up avenues for releasing pre-packaged microfluidic platform urine or blood testing devices. Conventionally, metal oxide semiconductor or MOS sensors are utilized to identify the linkage of biomolecules to a surface by estimating changes in charge, Linked of a silicon semiconductor layer, a glass insulator layer and a gold metal layer, such sensors are incorporated in an electrical circuit with the biomolecule sitting in an electrolyte – filled plastic well on above the sensor. If you can then apply a voltage and estimate current, you can work out the charge from the capacitance reading given off.
Biomolecules with distinct changes will offer you varying capacitance readings, allowing you to quantify the presence of biomolecules. The new sensor prepared by scientists in OIST’s unit, estimated charge utilizing the same method as traditional sensors but possess the additional function of estimating mass. Rather than having a solid gold metal layer, the so – called nano metal insulator semiconductor sensor possesses a layer of small gold metal islands. If you reflect light on such nanostructures, the surface electrons begin oscillating at a particular frequency. When biomolecules are added to such nano-islands, the frequency of such oscillations alters proportional to the volume of biomolecule. Based on this charge, you can utilize such method to estimate the mass of the biomolecule and confirm whether it survives exposure to ionized gas during encapsulation within the microfluidic platform.
“We offered a simple sensor that can answer very intricate surface chemistry questions,” says Dr. Nikhil Bhalla, an expert on creation of the nMIS sensor. The new nMIS sensor would be pre-packaged like a pregnancy test,” says lecturer Amy Shen, head of the OIST Unit. “If there is already something within it then you have to introduce whatever sample you are utilizing, like blood or urine.”
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