The patch we designed is an innovative composite detection nanomaterial composed of three layers : a bottom cellulose-based layer (support), an intermediate protein-based layer (linker), and a top antibody-based layer (detection) (Fig.1). To implement our project, we had to design and create each layer of our innovative patch.</br></br>

To produce the protein, we had to assemble the corresponding genes of each part of the fusion protein by using preexisting iGEM BioBricks. In fact, we assembled <a href="http://parts.igem.org/Part:BBa_K1028000"><B>BBa_K1028000</B></a> (encoding for Si4, from iGEM Leeds 2013), BBa_K863110 (encoding for CBPa, from iGEM Bielefeld-Germany 2012), and BBa_K103003 (encoding for BpA, from iGEM Warsaw 2008), and separated them by using flexible linkers in order to preserve their conformation and their biological activity. To make our protein easy to purify, the sequence of a HisTag was added at the 5’ end, followed by the TEV protease-specific cleavage site sequence to allow the removal of the HisTag after purification. To be certain of our protein’s expression, we intentionally added ATG initiation codons at the beginning and TAA stop codons at the end of the sequence. Next, cis-regulating elements, such as T7 terminator and T7 promoter, were taken from the pET43.1a(+) vector to flank the composite sequence, and iGEM prefix and suffix were added. BamHI and HindIII restrictions sites were added to the beginning and the end of final sequence, respectively2 (Fig 3). </br></br></br></br>