1, Purpose
We are developing biosensors.
Our purpose is to enable high sensitivity detection of Methicillin-resistant Staphylococcus aureus(MRSA) with the biosensor. Specifically, We want to quantify mrsa with amol order.(amok is 10 to the -18th power mol.)Currently, popular biosensors need amplify that number of the bacteria before detecting because of its sensitivity. The amplification need long time and professional and expensive equipment and advanced techniques.Long detection times compromise the speed of treatment and professional equipment and techniques lead to price increases.But if we can realize our biosensor, this amplification will be unnecessary and it will can save time , equipment and techniques.
Our purpose is to enable high sensitivity detection of Methicillin-resistant Staphylococcus aureus(MRSA) with the biosensor. Specifically, We want to quantify mrsa with amol order.(amok is 10 to the -18th power mol.)Currently, popular biosensors need amplify that number of the bacteria before detecting because of its sensitivity. The amplification need long time and professional and expensive equipment and advanced techniques.Long detection times compromise the speed of treatment and professional equipment and techniques lead to price increases.But if we can realize our biosensor, this amplification will be unnecessary and it will can save time , equipment and techniques.
2, Principle
Our biosensor detects the dna of mrsa as a target.
we detect this DNA with 2 kinds of nanoparticles. Particles of one species is magnetic-nanoparticle. This particle can stick to magnet.
Particle of the other species is Gold nanoparticle modified Ferrocene. Ferrocene can be easily detect with electro-chemical method.
These 2 kinds of nanoparticles are modified with base chains (It is called probe) that complementary to the targeting DNA. The 2 kinds of nanoparticles is connects with the target DNA and form complex.The complex is Easily isolateed using MNP and it is able to electrochemicaly detect using ferrocene on AuNP.
We execute the process of forming the complex using Micro-Total Analysis Systems(µ-Tas). µ-Tas is a technology that sets up channels and rooms on fine chips(It is a few cm order ), and perform transport, mixtuer, separation and reaction of them.
With this technology we have to only set the reagent at the inlet and press START BUTTON. In addition, It greatly reduce the amount of necessary reagents.
In the electrochemical detection, a positive voltage is applied to the complex and measure the generated oxidation current of ferrocene.
We use a screen printed electrod to measure trace samples. It is very small electrode less than 2 cm square.
we detect this DNA with 2 kinds of nanoparticles. Particles of one species is magnetic-nanoparticle. This particle can stick to magnet.
Particle of the other species is Gold nanoparticle modified Ferrocene. Ferrocene can be easily detect with electro-chemical method.
These 2 kinds of nanoparticles are modified with base chains (It is called probe) that complementary to the targeting DNA. The 2 kinds of nanoparticles is connects with the target DNA and form complex.The complex is Easily isolateed using MNP and it is able to electrochemicaly detect using ferrocene on AuNP.
We execute the process of forming the complex using Micro-Total Analysis Systems(µ-Tas). µ-Tas is a technology that sets up channels and rooms on fine chips(It is a few cm order ), and perform transport, mixtuer, separation and reaction of them.
With this technology we have to only set the reagent at the inlet and press START BUTTON. In addition, It greatly reduce the amount of necessary reagents.
In the electrochemical detection, a positive voltage is applied to the complex and measure the generated oxidation current of ferrocene.
We use a screen printed electrod to measure trace samples. It is very small electrode less than 2 cm square.
3, Results
Our ultimate goal is to detect 0.2 amol of DNA (a=10^-18).Currently, we could detect 100 amol of dna. We have to raise the sensitivity more and we are struggling.
Furthermore, it is necessary to reduce the detection time and the cost.
The current detection time is about 1 hour, and the cost is about 600 yen for just the reagent that for detection.
We used this system to detect MRSA and Staphylococcus aureus and confirmed that only MRSA can be selectively detected.
Furthermore, it is necessary to reduce the detection time and the cost.
The current detection time is about 1 hour, and the cost is about 600 yen for just the reagent that for detection.
We used this system to detect MRSA and Staphylococcus aureus and confirmed that only MRSA can be selectively detected.