Surface matters: passivation in carbon dot synthesis—a critical review

From fighting corrosion to illuminating cancer cells, can one material truly do it all? Carbon dots (CDs), with their unique properties, offer a promising answer to the escalating global challenges of environmental pollution and infrastructure degradation. Surface passivation, achieved through doping, is crucial in enhancing CD stability and photoluminescence. Doping with heteroatoms and metal ions modifies CD surface chemistry and electronic properties, resulting in improved fluorescence, stability, and anti-corrosion performance. This comprehensive review explores various doping techniques and their impact on CD properties, highlighting their diverse applications in anti-corrosion coatings, solar cells, bioimaging, sensing, and antibacterial agents. The review also addresses future perspectives and challenges in doped CD research, emphasizing the need for innovative doping strategies, scalable production methods, standardization, and successful device integration. The strategic manipulation of CD properties through doping will undoubtedly play a pivotal role in shaping the future of nanomaterial science and engineering, paving the way for innovative solutions to global challenges.