Two-way Nanoscale automata

In this paper, we show the all final subclass of two-way Watson-Crick automata have the same computational power as the classical two-way Watson-Crick automata. Here we compare the computational power of two-way Watson-Crick automata and two-way Quantum finite automata and we observe that two-way Watson-Crick automata can accept a language which two-way quantum finite automata cannot accept.