Scalability and application of silk fiber paper as a natural-based matrix for immunosensing

Abstract

The efficacy of immunosensors critically hinges on the employed immobilization matrix, which must ensure robust binding of biomolecules while preserving their functionality. Currently, various natural polymers are used as immobilization matrix for immunosensing due to their exceptional performance. Notably natural silk cocoon membranes (NCM) derived from Bombyx mori have emerged as a standout candidate for developing immobilization matrix. However, producing silk-based matrix involves complex processes, leading to challenges in achieving uniformity in shape and size, as well as difficulties in large-scale production, thereby limiting their broad applications.In this study, we employed a “hot-pressing” technique that integrates the thermal adhesion properties of sericin on partially degummed silk fibers with the mechanical performance of raw silk fibers as a scaffold to produce a natural based silk fiber paper (SFP). The fusion of these two materials enables the SFP to possess a three-dimensional structure similar to NCM, while maintaining its natural bioactivity, facilitating the development of an immobilization matrix for immunosensing. Characterization of the microstructural and physiochemical properties showed that the SFP exhibits consistent thickness, pore size, and hydrophilicity. It also exhibited favorable permeability for solution and red blood cells (RBCs), with an internal composition comparable to NCM. Colorimetric assays and RBC adsorption assays demonstrated that the immobilized capture antibody maintained its functionality effectively. The scalability of SFP production highlights its potential as a versatile and practical alternative to traditional immobilization matrix, paving the way for broader immunosensing applications.