A zero-step functionalization on paper-based biosensing platform for covalent biomolecule immobilization

As a potential platform for point-of-care clinical analyses and environment monitoring, paper biosensors have received considerable attention. In many cases, the conjugation of biomolecules onto paper surface is crucial for increasing the functionalities of paper-based bioanalytical devices. Until now, it is sometimes argued as in the literature that finding a surface chemistry for biomolecule covalent grafting to paper still remains a challenge. Here the study shows that at least to a certain extent some aspects of the argument involved is questionable, by demonstrating that paper without any modification could be utilized for the covalent conjugation of enzymes and serves as a tool for bioanalysis. Moreover, the detailed analysis of biomolecule immobilization strategies on paper through polysaccharide-coating chemistry has been offered as a contrast. We believe that the proposed method could provide a valuable perspective for paper-based biosensors.