Objective

Once the aptamer has been successfully discovery, improve and tested, we’ll need a way to integrate into an IoT device. IoT has multiple requirements and we could extrapolate some of them into the measurement system; The system has to be affordable, automatic and the limit of detection must be under the range of the protein’s concentration in the air.

Although our first idea includes an opticalsystem to measure the protein present in the sample, this approach has three main limitations

1. The detection limit of this system is over the protein concentration that we need to measure.

2. The optically systems are fine for working at the lab, but the unstable street conditions introduce so much noise in the system.

3. Is complicated to maintain an optical system stable outside a laboratory. The mechanics of the optics tend to decalibrate.

The electrochemical system has been conceived to solve these difficulties.

The Electrodes

The main part of the system is the electrodes above which we bound the aptamers, the called “Working electrodes”. Additionally, for taking the measurements with a potentiostat, we need another 2 electrodes, the “Reference electrode”, and the “Auxiliary electrode”.

From now to the future the word “electrode” will represent this 3 electrode system.

This system of three electrodes its sold together in ceramic boards. We have ordered them to DropSens,which is a Spanish business and a global referent in the field. Across the large repertoire, we have chosen electrodes with the following characteristics:

1. The working electrode is made of carbon with gold nanoparticles. The carbon has a better electrochemical window than gold or silver (check this postfor more information) and gold are the ideal substrate to join DNA (It only have to be thiolated).

2. The auxiliary electrode is also made of carbon.

3. The reference electrode is made of silver.

The DropSens reference of our electrode is 110GNP and you could see the complete datasheet here.