A novel fluorescence biosensor for the detection and imaging of tumor-related mRNA in living cells based on Au//hGNPs-FA nanocarrier

•New matching scheme of AuNPs and hGNPs not only utilizes the powerful load capacity of hGNPs, but also realizes the purpose of efficient sealing and highly specific release.•A novel fluorescent sensor is fabricated and could detect tumor-related mRNA in living cells with high specificity and sensitivity.•Combined with FA, the efficiency of Au//hGNPs entering cells was increased by 20%. Au//hGNPs-FA nanocarriers-based novel fluorescence strategy for the detection and imaging of tumor-related mRNA in the living cells is described. Au//hGNPs-FA is a new nanocarrier with large capacity, high release efficiency and specificity. In Au//hGNPs-FA, ssDNA-bound gold nanoparticles (AuNPs-T1) could tightly combine with ssDNA-bound hollow gold nanospheres (hGNPs-T2) by hybridization of T1 and T2. Since AuNPs of diameter 16 nm could block the hGNPs’ pores of diameter 8.4 nm, the non-specific release of signal substances can be significantly reduced. New matching scheme of AuNPs and hGNPs not only utilized the powerful load capacity of hGNPs, but also realized efficient sealing and specific release. The results of extracellular experiments showed that the method can detect mRNA standards in the range of 1 pM to 20 nM, and the minimum detection limit is 850 fM. More importantly, combined with FA, the efficiency of Au//hGNPs-FA entering cells was increased by 20%. And, the fluorescence strategy could detect mRNA in living cells with high specificity and sensitivity, even in single cell with very low content. Therefore, the new strategy has the potential to monitor the expression of mRNA in tumor cells accurately.