碳量子点的光致发光性质不仅决定于尺寸还依赖于它的表面态，因此通过在碳量子点表面掺杂或嫁接不同元素与基团有望调节它的荧光发射行为。为了研究多种元素掺杂对碳量子点发光性质的影响，本文以对氨基苯磺酸为原料，通过水热法一步合成了氮、硫共掺杂的碳量子点。实验结果表明: 制备的碳量子点尺寸分布均匀，氮、硫分别以氨基和磺酸基团的形式存在于碳量子点的表面。与已有的报道不同，碳量子点展现出了非激发波长依赖的蓝光发射行为，三价铁离子可有效猝灭其荧光，铁离子浓度在0~10-3 mol·L-1范围内与碳量子点的荧光猝灭程度呈现良好的线性关系，检出限约为10-7 mol·L-1。制备的碳量子点对三价铁离子具有高选择性、高灵敏性以及较好的抗干扰能力，能作为三价铁离子检测的传感器。

Not only do the photoluminescence (PL) properties of carbon quantum dots (CQDs) depend on their sizes, but also rely on their surface states. Accordingly, the PL behaviors of CQDs could be tuned by doping and/or grafting heteroatoms and groups. In this work, sulfur-and nitrogen-co-doped carbon quantum dots (SN-CQDs) were firstly synthesized by one-step hydrothermal method using p-aminobenzenesulfonicacid as carbon source. Experimental results indicate that the obtained SN-CQDs have a uniform size and are modified by amine and sulphonic acid groups at their surface. Unlike previous reports, the SN-CQDs show the excitation-wavelength-independent photoluminescence behavior and their fluorescence can be quenched by Fe3+ ions. There is a good linear relationship between the Fe3+ concentrations within 0-10-3 mol·L-1 and the fluorescence quenching rates of SN-CQDs. The detecting limit for Fe3+ ions is about 10-7 mol·L-1. The obtained SN-CQDs have the ability of high selectivity, high sensitivity and good anti-jamming capability to ferric iron ions. Accordingly, SN-CQDs can be used for the detection of Fe3+ ions in the environment and organism.