Generation of the Signal
The binding of the pathogen should induce a signal that could be recognised without any sophisticated technical instruments. Because of the size of pathogens and the frequency of binding events a simple signal cascade will not suffice - signal amplification is necessary.
This signal amplification can be achieved by usage of redox reactions that are generated after the binding event. A close contact between recognition structures and redox partners is ensured by coupling all molecules to the same polymer scaffold. This close contact guarantees the efficient transfer of chemical and electric signals. At the end of the redox reaction cascade a coupled enzyme reaction occurs that induces a visible colour reaction.
But it is also possible to bypass redox reactions by using chromophore systems. With the binding of the pathogen, changes in the direct chromophore environment are induced that change their absorption or emission spectrum. These changes could be directly recognised.