Brightly near-infrared to blue emission tunable silver-carbon dot nanohybrid for sensing of ascorbic acid and construction of logic gate.

Recently, carbon dots (CDs) have drawn extensive attention owing to their unique properties. While more and more research had been focusing on the exploration of CDs as fluorescence sensors, the blue or green fluorescence emission of CDs restricts further applications of CDs, particularly in the biology-relevant fields due to the commonly blue auto-fluorescence of biological matrix. Therefore, the preparation of CDs with strong emission at long wavelengths is highly desirable. For these situations, a facile, straightforward and extra-reductant needless method was established to fabricate silver-carbon dot nanohybrid with enhanced near-infrared fluorescence through metal-enhanced fluorescence (MEF). We applied the Ag-CD nanohybrid as a probe to detect antioxidants such as ascorbic acid in near-infrared window, and the probe possesses a linear range of 0.2-60μM. More importantly, this sensor could not only function in aqueous solution, but also display well selective response in intricate biological fluids. In addition, an IMPLICATION logic gate was constructed based on the unique characteristics of Ag-CD nanohybrid which presages more opportunities for application in single and multiple biological sensing.