Three-Dimensional ZnInS Nanoflakes@Carbon Fiber Frameworks for Biocatalytic Precipitation-Based Photoelectrochemical Immunoassay

Three-dimensional (3D) nanostructured materials have recently attracted intensive research interest in various fields. For the photoelectrochemical (PEC) bioanalysis, unique 3D nanostructured semiconductors are also of special appeal because they allow direct mass transport and offer large surface areas for biomolecular immobilization. Currently, two-dimensional and 3D metal-sulfide semiconductor materials have drawn tremendous interest because of their different chemophysical features. This work presents the innovative fabrication of 3D ZnInS nanoflakes (NFs)@carbon fiber (CF) frameworks and its validation as a unique 3D platform for the biocatalytic precipitation (BCP)-based PEC immunoassay. Experimental results revealed that the as-developed 3D framework photoelectrode was advantageous for the accommodation of biomolecules and in situ deposition of BCP. The corresponding BCP growth process on the photoelectrode was also systematically characterized. Exemplified by lipoprotein-associated phosPhohPaseA2 (LpPLA2), the as-derived PEC immunoassay exhibits good analytical performance. This study features the first fabrication of 3D ZnInS NFs@CF frameworks for advanced BCP-based PEC bioanalysis and is expected to inspire more interest in the development of 3D nanoframework photoelectrodes for future PEC bioanalysis development.