(Invited) Application of Nanostructure for Improving the Interfacial Interactions between Sensing Surface and Targeted Particles

Various interfacial interactions, encompassing screened Coulomb (electrostatic double layer) forces, Lifshitz-van der Waals forces, hydrophobic/hydrophilic interactions, as well as steric, chemical, morphological, and roughness effects, have been confirmed to play a crucial role in governing the interaction between target particles and the sensing surface. Small protrusions on the sensing surface can induce substantial variations in the surface’s interaction with the target analytes based on the extended Derjauin-Landau-Verwey-Overbeek (DLVO) theory. 1 Here, indium tin oxide coated vertical nanowires served as nanostructure to investigate interfacial interactions between the sensing surface and targeted analytes. Analyzing the ratio of particle size to asperity size on the sensing surface within the extended DLVO theory revealed that surface roughness can provide sufficient interfacial interactions with target analytes, thereby enhancing the electrical sensing performance. Upon immersing the nanostructural sensing surface in an analyte solution, electrical signals undergo a significant shift owing to alterations in the surface potential at the interface between the functionalized sensing surface (such as antibodies or chemical functional groups) and the analyte solution. 2, 3 These observations highlight the critical role of nanostructure on the sensing surface, particularly with adequate surface roughness, in significantly improving sensing performance by facilitating effective interaction of the surface with the target analyte based on the extended DLVO theory. References: Huang, X.; Bhattacharjee, S.; Hoek, E. M. V., Is Surface Roughness a “Scapegoat” or a Primary Factor When Defining Particle−Substrate Interactions? Langmuir 2010, 26 (4), 2528-2537. Lin, S.-P.; Lee, W.-J.; Sun, M.-C.; Yang, Y.-H.; Vinzons, L. U.; Lin, Y.-M.; Wei, Y.-T., Nano-Brush Structure for Rapid Label-Free Differentiation of Alzheimer’s Disease Stages and Direct Capture of Neuron-Derived Exosomes from Human Blood Plasma. ACS Applied Materials & Interfaces 2023, 15 (48), 56478-56489. Yang, Y.-P.; Lu, Y.-L.; Kumar Gupta, A.; Lin, S.-P., Real-Time Impedimetric Detection of Cardiac Troponin I Using ITO-Coated Vertically Aligned Silicon Nanowires. Mater. Lett. 2022, 311 , 131575.