(275f) Tailored Synthesis of Multi-Color Emissive Carbon Dots for Efficient and Rapid Photothermal Nucleic Acid Amplification

This study focuses on the development of multi-color emissive carbon dots (CDs) with systematically tailored chemical and physical properties. Through a modified temperature and acid reagent engineered hydrothermal synthesis protocol, highly stable, cost-effective, and environmentally friendly CDs were synthesized to actuate photothermal polymerase chain reaction (PCR). Optical, physical, chemical and thermal characterizations were conducted to investigate their light-to-heat conversion performance. Results showed that red-emitting CDs had significantly higher light-to-heat conversion efficiency than their blue, cyan, green, and yellow counterparts. The study further revealed that increased acid treatment during the fabrication of CDs enhances aromatization and introduces stronger electron-donating functional groups, leading to a more conjugated and oxidized carbon dot structure. This bandgap engineering strategy reduces the HOMO-LUMO band gap, destabilizing the electrons in Ï€-Ï€* orbitals and increasing the frequency of electron-phonon coupling. This coupling generates thermal vibration in the carbon dot lattice, initiating temperature increase in macroscopic scale. The resulting red-emitting carbon dots yielded high heating ramp rates of 13 °C/s when illuminated with a 350 mW blue laser. Finally, these nanocarbons were employed as efficient photothermal nanomaterials to achieve ultrafast thermocycling for quantitative real-time PCR, capable of performing 30 cycles of 95 °C to 60 °C in less than 10 minutes. The study highlights the potential of carbon dots as a sustainable and cost-effective alternative to traditional PCR methods and sets the stage for the bandgap engineering and utilization of carbon dots as efficient and effective nanomaterials for future photothermal applications.