Electrochemical Sensing Mechanisms and Interfacial Design Strategies of Mesoporous Nanochannel Membranes in Biosensing Applications

ConspectusPrecise and rapid detection of key biomolecules is crucial for early clinical diagnosis. These critical biomolecules and biomarkers are typically present at low concentrations within complex environments, presenting significant challenges for their accurate and reliable detection. Nowadays, electrochemical sensors based on nanochannel membranes have attracted significant attention due to their high sensitivity, simplicity, rapid response, and label-free point-of-care detection capabilities. The confined arena provided by the nanochannels for target recognition and interactions facilitates detection and signal amplification, leading to enhanced detection performance. The nanochannel membranes also can act as filters to repel the interferents and enable target detection in more complex environments. Thus, sensors based on nanochannel membranes are considered promising platforms for biosensing applications. However, challenges such as uncontrollable structures and unstable performance in some materials limit their applications and theoretical advancements. To investigate the relationship between architecture and sensing performance and to achieve reliable and efficient performance, it is essential to construct sensors with precise nanostructures possessing stable properties. With the development of nanomaterials technology, mesoporous nanochannel membranes with robust, controllable, and ordered mesostructures, along with tunable surface properties and tailored ion transport dynamics, have emerged as promising candidates for achieving reliable and efficient biosensing performance. Additionally, investigating the sensing mechanisms and key influencing factors will provide valuable insights into optimizing sensor architecture and enhancing the efficiency and reliability of biosensing technologies. In this Account, we highlight substantial advancements in mesoporous nanochannel membranes, which are mainly based on the research work published by our group. In the first section, we explore the underlying mechanisms of the sensing processes, including the solid-liquid interfacial interactions and nanoconfinement effects (i.e., electrostatic interactions, hydrophilic/hydrophobic interactions, and steric hindrance effects). We also delve into the key parameters including geometry, materials, recognition elements, and external factors related to mesoporous nanochannel membranes and their impacts on sensing mechanisms and performance. In particular, we point out that mesoporous nanochannel membranes with three-dimensional interconnected networks can facilitate ion penetration and lead to an increased number of binding sites, contributing to high sensitivity. Additionally, composite or multilevel mesoporous nanochannel membranes, particularly when integrated with external stimuli such as pH, light, and heat, can introduce unexpected properties, enhancing the sensing performance. These understandings provide valuable insights into the fundamental principles and influencing factors pertinent to the research and design of intelligent, high-quality sensors or nanofluidic devices. Furthermore, we conduct an analysis of integrating various biosensing mechanisms and strategies, which offers significant opportunities for biomedical monitoring, disease diagnosis, and the pharmaceutical industry. Finally, we describe future research directions and their potential for commercial adoption. Nanochannel sensors with novel structures, properties, and functional porous materials may lead to new trends in biomedical applications, including self-powered and wearable sensors for disease monitoring. We believe that this Account holds implications for promoting interdisciplinary endeavors encompassing chemistry and materials science and nanotechnology as well as analysis, biosensing, and biomedical science.