Nanofluidic Chip with Ripple Nanostructures Fabricated by Atomic Force Microscopy Tip-Based Nanoscratching for Label-Free Deoxyribonucleic Acid Detection

The nanofluidic chip holds immense potential for applications in disease diagnosis, bioanalysis, and environmental detection due to its advantageous nanoscale size. The key component enabling the performance of a nanofluidic chip is the nanochannel. In this study, we fabricated controllable and consistent arrays of nanochannels, termed nanoripple structures, using an atomic force microscopy (AFM) probe reciprocal scanning approach. Furthermore, we successfully fabricated a nanofluidic chip with a nanochannel array by combining photolithography, transfer, and bonding techniques. We verified the feasibility of the prepared nanofluidic chip through ionic conduction experiments. Additionally, we compared the performance of the nanofluidic chip with a single channel to that of a chip with a nanochannel array through ionic conduction experiments to demonstrate the high sensitivity achieved by incorporating a nanochannel array. Moreover, we conducted DNA molecule detection experiments by modifying the nanochannel surface, which lays down the foundations for expanding applications of AFM-based Nanomachining technology in nanopore sensing.