Biologically, there exist two kinds of syntheses: photosynthesis and ATP-driven biosynthesis. The light harvesting of photosynthesis is known to achieve an efficiency of ~ 95% by the quantum energy transfer of photons. However, how the ATP-driven biosynthesis reaches its high efficiency still remains unknown. Deoxynucleotide triphosphates (dNTPs) in polymerase chain reaction (PCR) adopt the identical way of ATP to release their energy, and thus can be employed to explore the ATP energy process. Here, using a gold nanoparticle (AuNP) enhanced PCR (AuNP-PCR), we demonstrate that the energy released by phosphoanhydride-bond (PB) hydrolysis of dNTPs is in form of photons (PB-photons) to drive DNA replication, by modulating their resonance with the average inter-AuNP distance (D). The experimental results show that both the efficiency and yield of PCR periodically oscillate with D increasing, indicating a quantized process, but not simply a thermal one. The PB-photon wavelength is further determined to 8.4 μm. All these results support that the release, transfer and utilization of bioenergy are in the form of photons. Our findings of ATP-energy quantum conversion will open a new avenue to the studies of high-efficiency bioenergy utilization, biochemistry, biological quantum physics, and even brain sciences.