Anomalous Elastic Properties of Attraction-Dominated DNA Self-Assembled 2D Films and the Resultant Dynamic Biodetection Signals of Microbeam Sensors

Abstract

The condensation of DNA helices has been regularly found in cell nucleus, bacterial nucleoids, and viral capsids, and during its relevant biodetections the attractive interactions between DNA helices could not be neglected. In this letter, we theoretically characterize the elastic properties of double-stranded DNA (dsDNA) self-assembled 2D films and their multiscale correlations with the dynamic detection signals of DNA-microbeams. The comparison of attraction- and repulsion-dominated DNA films shows that the competition between attractive and repulsive micro-interactions endows dsDNA films in multivalent salt solutions with anomalous elastic properties such as tensile surface stresses and negative moduli; the occurrence of the tensile surface stress for the attraction-dominated DNA self-assembled film reveals the possible physical mechanism of the condensation found in organism. Furthermore, dynamic analyses of a hinged–hinged DNA-microbeam reveal non-monotonous frequency shifts due to attraction- or repulsion-dominated dsDNA adsorptions and dynamic instability occurrence during the detections of repulsion-dominated DNA films. This dynamic instability implies the existence of a sensitive interval of material parameters in which DNA adsorptions will induce a drastic natural frequency shift or a jump of vibration mode even with a tiny variation of the detection conditions. These new insights might provide us some potential guidance to achieve an ultra-highly sensitive biodetection method in the future.

Clamped-end effect on static detection signals of DNA-microcantilever

“…In addition, according to the experiments for the DNA film under uniaxial compression shown in Refs. [25] and [28], the adsorption-induced axial stress of the DNA film can be easily obtained as…”

“…w is the z-direction displacement. Second, according to the previous studies [28] , the deformation potential energy of the whole microcantilever can be written as…”

The Fabrication of Micro Beam from Photopolymer by Digital Light Processing 3D Printing Technology

“…Many studies have been conducted, especially in the field of DNA [38][39][40]. In a study, a multi-scale analytical model was created to define the relationship between the surface mechanical features of DNA self-assembled 2D films and the detection signals of DNA-micro beam systems [41]. Micro beams exactly predict the dynamic properties of the device, such as its natural frequencies and forced-vibration response.…”