Virtus-Parva During the length of our project, we found that importing chemicals reagents and biological agents that we needed were difficult to pass through customs. In coordination with other Mexican teams, specially Tec-Monterrey Team we propose to a local Deputy Patricia Leal Islas a change in customs law, to make it easier for future iGEMers and other scientists to continue with their investigations.

As we were transforming our E. coli cells, we noticed it wasn’t as fast and efficient as we had hoped, which is how we came up with module two of the project. Quite simply, we wanted to take advantage of the shape of our system and its mobility thanks to magnetism in order to make a more efficient transformation. We were able to verify our method was more efficient by making cells express GFP and RFP, which can then be quantified with optic instruments.

NEMS are nanometric electromechanical systems. In this case we take as basis the structure of a resonator which are engineered to make a conversión between energy, such as electric, magnetic, or vibrational into mechanical response.

How exactly do NEMS come into play in our project?

Well, by combining an inorganically synthesized nanoparticle, called magnetite and DNA into what we call BioNEMS drill.

Contenido subtitulo 2

The first part of the synthesis of our magnetite was trying out different methods and characterizing them, to note which method had given us the smallest size nanoparticles. Our first method was synthesis by coprecipitation, of which we prepared nine samples with different concentrations of iron(II) chloride and ammonium hydroxide; from this method we consistently obtained nanoparticles rounding 0.9 to 1nm. Our following method was very similar, but included water in the synthesis: the size of our particles would vary greatly, from 3.89 micrometers to 171 nanometers in size.

After choosing the best method possible, it was time to silanize our magnetite in order for it to be biocompatible with DNA and be able to tie them together. In order for the silanization to take place, we used a solution of TEOS (tetraethoxysilane) dispersed in a medium of water and propanol and dripped this mix slowly onto our magnetite. Just like when we synthesized our particles, we tested different concentrations of TEOS and magnetite, as well as different addition rates in order to observe which combination would give us the smallest possible nanoparticles.

Our results were then characterized by DLS (dynamic light scattering), for which we observed a peak at 39 nm, once coated with TEOS, the peak was moved toward 60 and 80 nm. We also ran our two samples in the IR, comparing the spectra of the pure magnetite and silanized magnetite, we were able to distinguish a peak at 990.2 cm^-1 corresponding to a Si-O bond, confirming the correct silanization of the magnetite.

Soon..