Effect of contact resistance on the electrical conductivity of polymer graphene nanocomposites to optimize the biosensors detecting breast cancer cells

Abstract

This study focuses on the contact regions among neighboring nanoparticles in polymer graphene nanocomposites by the extension of nanosheets. The resistance of graphene and the contact zones represent the total resistance of the prolonged nanosheets. Furthermore, the graphene size, interphase depth, and tunneling distance express the effective volume portion of graphene, while the onset of percolation affects the fraction of percolated nanosheets. Finally, a model is developed to investigate the conductivity of the samples using the graphene size, interphase depth, and tunneling size. In addition to the roles played by certain factors in conductivity, the experimental conductivity data for several samples confirm the conductivity predictions. Generally, the polymer sheet in tunnels determines the total resistance of the extended nanosheets because graphene ordinarily exhibits negligible resistance. In addition, a large tunnel positively accelerates the onset of percolation, but increases the tunneling resistance and attenuates the conductivity of the nanocomposite. Further, a thicker interphase and lower percolation threshold promote the conductivity of the system. The developed model can be applied to optimize the biosensors detecting the breast cancer cells.

Novel olive stone biochar particle network for piezoresistive strain sensing in natural fiber‐reinforced composites

“…This should work in favor of the smaller particle size. [61][62][63][64][65] The opposite trend is found. This may be partly due to the different intrinsic conductivities of the particles.…”

“…Intrinsic bulk resistance and contact (e.g., tunneling junction) resistance add up to the total resistance of the network. 62,63 The intrinsic bulk resistance of biochar might have an effect on the network resistance. However, it is very likely that the shift between CB and biochar results at least partly from a high contact resistance, or a broad contact resistance distribution in the case of biochar.…”

Simulating of effective conductivity for graphene–polymer nanocomposites

“…However, the wonderful conductivity of graphene mainly deteriorates its inherent resistance, which cannot produce a www.nature.com/scientificreports/ considerable opposition affecting the conductivity. Really, the negligible resistance of graphene nanosheets cannot act against the electron current 54,55 . Consequently, the model satisfactorily shows the ineffectual weight of high graphene conductivity in the efficient conductivity.…”

Percolation onset and conductivity of nanocomposites assuming an incomplete dispersion of graphene nanosheets in a polymer matrix

“…34,35 Moreover, electrons can be transferred between neighboring nanosheets in the polymer nanocomposite by the tunneling effect. [36][37][38][39] So, the nanosheets can produce the nets in nanocomposites even at a small distance between nanoparticles. However, the conductivity considering the interphase areas and tunneling effect has not yet been studied.…”