  We propose novel chemical reaction networks to translate levels of
concentration into unique DNA strand species, which we call concentration
translators. Our design of the concentration translators is based on
combination of two chemical reaction networks, consensus network and conversion
network with any number of chemical species. We give geometric analysis of the
proposed CRNs from the viewpoint of nonlinear dynamical systems and show that
the CRNs can actually operate as translator. Our concentration translators
exploit DNA strand displacement (DSD) reaction, which is known for a universal
reaction that can implement arbitrary chemical reaction networks. We
demonstrate two specific types of concentration translators (translator A and
B) with different switching behavior and biochemical cost and compared their
characteristics computationally. The proposed concentration translators have an
advantage of being able to readout the concentration of targeted nucleic acid
strand without any fluorescence-based techniques. These characteristics can be
tailored according to requirements from applications, including dynamic range,
sensitivity and implementation cost.
