A self-powered millifluidic device driven by triboelectric generator for the label-free and real-time detection of DNA hybridization

In this paper, a novel, versatile, easy-to-operate, highly sensitive triboelectrification-induced platform is suggested for the detection of DNA hybridization without electric poling and labeling the targeted DNA. Singlestranded DNA probes are tethered on PBASE-functionalized graphene electrode surface via intermolecular interactions to specifically capture the complementary target DNA sequence. For this purpose, the biosensing interface is set up in a millifluidic chamber, integrated into the dual-mode conductor-to-dielectric triboelectric generator to stimulate the genosensor and scavenge the signal simultaneously. Numerical simulations are carried out using a two-dimensional model in COMSOL Multiphysics software. In line with the heterogeneous genoassay modeling, flow variables are tuned to attain the optimal hybridization efficiency equal to 92%. The formation of an electric double layer at the electrode-electrolyte interface is figured out through mechano-triboelectric transduction so that the generated output signal is proportional to the target DNA concentration. Accordingly, DNA: DNA duplexes could be addressed at concentrations as low as 10 pM in PBS solution (pH 7.4) with an ultrahigh sensitivity of 1.469 VnM-1cm-2 and linearity over the full testing concentration range, 30 pM-10 nM, for the contact-separation scheme. The results of sequence mismatch analysis at the nucleotide level confirm the salient specificity of the proposed sensor chip taking the length of probe/target strands and binding constants of the hybridization reaction into account. The self-powered genosensor can offer a vast clinical potential use, in particular in the timely diagnosis of inherited diseases, genotyping of pathogens, identification of co-infections, and cancer screening, ranging from outbreak management to therapeutic orientation and patient follow-up.