Integrating graphene oxide with an enzyme-free DNA circuit for the development of universal fluorescence biosensor

• Built a sensitive fluorescence biosensor by using GO as fluorescence quencher and CHA achieving cyclic signal amplification. • The sensing platform can be fabricated all-in-one based on TMSD. • A universal sensing platform can be developed which provides excellent performance for sensing miRNA, adenosine and thrombin. A sensitive, universal and all-in-one fluorescence biosensor was constructed by using graphene oxide (GO) as fluorescence quencher and catalytic hairpin assembly (CHA) to achieve cyclic signal amplification. In this sensing system, highly specific toehold-mediated strand displacement (TMSD) was combined using the technique of indirect DNA immobilization by capture DNA, which prevents non-specific DNA adsorption on the GO, to provide an excellent reaction efficiency of CHA for one-pot. This new method is general and has been successfully applied for the selective detection of miRNA-21, adenosine and thrombin with detection limits of 0.66 pM, 1.2 μM and 0.14 nM respectively, demonstrating its great application prospects for biomolecular recognition in diagnostic analysis.