Engineering a biological detector using the piezo phototronic effect in DNA chains

Piezophototronic is an emerging field that has attracted the attention of many researchers in recent years. This phenomenon is based on the simultaneous effect of light radiation and mechanical stress on the electrical transport of semiconductors. In this work, the piezo phototronic phenomenon in biological DNA chains is studied. By simultaneously investigating these two external stimuli, the best conditions for flowing electric current through DNA sequences can be obtained and used to design optical and piezoelectric (piezo phototronic) detectors.

Method & Materials: 

In this work, we study the electrical current through different DNA sequences by simultaneously investigating the effect of mechanical stress and light radiation. We use the Hamiltonian model of Peyrard, Bishop and Dauxois (PBD) modified by the effects of electric field of light radiation by laser and mechanical stress caused by an external force. Then, by obtaining the evolution equations of the system and calculating the electric current through the sequence, we study the electrical transport of the system.

The results show that pseudo-ohmic regions are observed in the current-voltage characteristic diagram through the voltage variation, which can be used for designing a trivial electrical device. Then, with increasing voltage, the slope of the current-voltage characteristic diagram changes to negative. In other words, we observe negative differential resistance (NDR) phenomenon in some parameter values. The NDR region can be used for designing controllable switches. Again, with increasing voltage, we observe that such regions repeat periodically. The highest current flows through the CG-20 bp sequence at room temperature (300K) and with increasing temperature, the current through the sequence decreases.

Mechanical stress and light radiation can be influential factors on the electrical transport of a biological system based on DNA. It can be said that by adjusting the intensity and frequency of the applied force and light radiation, the current through the system can be controlled, which is useful in designing piezo phototronic devices. Piezo phototronic devices are one of the main components of detectors and biosensors that can play a significant role in diagnosing diseases and their causes.