Highly bendable and smoke free degradable nanomaterials modified paper based electrochemical biosensor for efficient detection of protein biomarker.

[Display omitted] • PEDOT:PSS and Borophene nanosheets modified conducting paper. • Cost efficient and flexible biosensor for protein biomarker detection. • Environment friendly biosensing platform with smoke free degradation. • Ultralow LOD (0.49 ng ml−1) and wider LDR (1 ng ml−1 - 60 µg ml−1) for swine flu detection. Here, we report results of the studies related to the fabrication of nanomaterial modified paper [Whatman paper modified with poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) and Borophene nanosheets] based biosensor for proteinaceous Serum Amyloid A (SAA) biomarker detection. For the fabrication of stable and cost-efficient nanomaterial modified conducting paper, we used simple dip coating method followed by solvent treatment. The incorporation of Borophene nanosheets onto the conducting paper resulted in enhance electrochemical performance, flexibility and signal stability. The flexibility of fabricated electrode is validated via bending and folding studies; it continues to maintain conductivity even after being folded 40 times. Furthermore, this paper sensor may be quickly and properly disposed of by simple burning method without emitting smoke. It was also observed that no any harmful/heavy element was present after disposal of the paper sensor. During fabrication of paper based sensor, anti-SAA was physically immobilized and further bovine serum albumin (BSA) was used to block the non-specific binding sites. To examine structural and morphological features of the synthesized material and the fabricated paper electrodes; X-ray diffraction, transmission electron microscopy, scanning electron microscopy, contact angle, and Fourier-transform infrared spectroscopy were used. The fabricated immunoelectrode (BSA/anti-SAA/Borophene/CP) is highly efficient to detect SAA with ultralow limit of detection of 0.49 ng mL−1, wider linear detection range in between 1 ng mL−1 - 60 µg mL−1 and high durability of 42 days. Finally, SAA protein in spiked serum samples was analyzed using the fabricated immunosensor, and the obtained results show good correlation with the standard SAA protein samples. [ABSTRACT FROM AUTHOR]