Nanoparticle-based arbitrary nanostructures for electrochemical biosensors

Electrochemical biosensors have gained widespread application in analytical chemistry and bio-diagnosis due to their rapid, sensitive, and selective detection capabilities. The electrode structures of the biosensors play a pivotal role in determining signal transduction and sensing performance. With the rapid recent advancement in nanotechnology, the electrode structures particularly the structures on the electrodes have increasingly shifted towards the arbitrary nanoscale configurations. This trend is driven by the pursuit of achieving exceptional analytical performance, including ultra-low detection limits and heightened sensitivity. The nanostructures on the electrodes offer abundant active sites, superior electron transport properties, and diverse surface modification options. Nanoparticles are widely employed to construct high-performance nanostructures for electrochemical biosensors according to their high surface-to-volume ratios, tunable morphology, and enhanced catalytic activity. This review systematically discussed various nanoparticle-based nanostructures applied in electrochemical biosensors, including scaffold nanostructures, polymer nanostructures, and bionic nanostructures. The nanostructures on the electrode surface are primarily categorized into two-dimensional (2D) and three-dimensional (3D) configurations. A comprehensive analysis is conducted on the structural evolution, the functional roles of nanoparticles within these architectures, and their effect on biosensing performance. Moreover, the challenges and perspectives for the development of electrochemical biosensors utilizing nanoparticle-based nanostructures were discussed.