Biomimetic synthesis of protein-DNA-CaHPO hybrid nanosheets for biosensing: Detection of thrombin as an example.

Traditional strategies for coupling of proteins with DNA involve the additional modifications on protein or DNA to construct protein-DNA conjugates, resulting in complex or time-consuming coupling process. This study presented a biomimetic synthesis strategy to elaborately synthesize a new type of biomolecule-inorganic hybrid nanosheets. Horseradish peroxidase (HRP) and DNA aptamer can be easily combined with CaHPO via coprecipitation simultaneously to form all-inclusive HRP-aptamer-CaHPO hybrid (HAC) nanosheets integrating bifunction of biorecognition and signal amplification, which was proceeded in the green environment at room temperature and required no additional modifications on CaHPO, protein and DNA. Therefore, it avoided tedious linking and purification procedures. The HAC nanosheets were then employed as the signal labels and showed excellent performance for detecting thrombin. This bioinspired approach provides great possibilities to facile and efficient immobilization of protein, DNA or even other types of biomolecules (e.g., RNA and peptide) on inorganic nanomaterials and endows great potential in the preparation of a variety of multifunctional biomolecule-CaHPO two-dimensional (2D) nanobiohybrids for various applications extending from biosensing to energy, biomedicine, environmental science and catalysis.