Silk fibroin as a platform for dual sensing of vitamin B₁₂ using photoluminescence and electrical techniques

The amalgamation of natural origin materials and technologies for label-free and real time detection is pertinent in analytical field. In this study, Bombyx mori silk fibroin protein (BMSF) has been utilized for the dual sensing of vitamin B₁₂ via fluorescence and electrical impedance techniques. The processing of BMSF is done to generate an aqueous solution of BMSF along with the development of micro patterned thin films via soft lithography technique. The BMSF aqueous solution exhibit auto fluorescence property and thereby utilized for label free detection of vitamin B₁₂ with an estimated limit of detection (LOD) of about 0.003 × 10^-6 g/uL. This is followed by impedimetric detection of vitamin B₁₂ using the micro patterned BMSF thin films. A LOD of 17.8 ppm and 0.25 ppm are achieved in aqueous solution and human blood serum, respectively. Taken together, this work demonstrates a potential label free dual sensing mode for sensitive detection of micronutrient vitamin B₁₂.