The fluorescent boron, nitrogen and sulfur co-doped carbon dots (BNSCDs) were prepared by simple hydrothermal reaction of 4-carboxyphenylboronic acid and 2,5-diaminobenzenesulfonic acid at 200 ^oC for 8 hours. The fluorescence of the BNSCDs could be quenched by Fe³⁺ based on the electron transfer between Fe³⁺ and BNSCDs, so a label-free, good selectivity and high sensitivity method for Fe³⁺determination was established with linear range and LOD of 1.5 - 692 μmol/L and 87 nmol/L, respectively. And then the fluorescent probe was employed for detection of Fe³⁺ in tap water, coal gangue, fly ash and food samples successfully. Moreover, the as-prepared BNSCDs could serve as a novel pH fluorescent probe in the range of pH 1.60-7.00, which could be attributed to the proton transfer of carboxyl groups on the surface of BNSCDs. More importantly, the pH fluorescent probe possesses fast, real-time and low toxicity, applying for intracellular pH fluorescence imaging in HIC, HIEC, LO2 and SMMC7721 cells. In view of its simplicity, timely response and outstanding compatibility, the as-fabricated BNSCDs show the potential applications in water quality and solid waste monitoring, food detection, real-time measuring of intracellular pH change in vitro.

荧光硼，氮和硫共掺杂碳点（BNSCD）是通过4-羧基苯基硼酸和2,5-二氨基苯磺酸在200 ^o C进行简单的水热反应8个小时而制得的。所述BNSCDs的荧光可以被Fe猝灭³⁺基于Fe之间的电子转移³⁺和BNSCDs，所以对于铁无标记，良好的选择性和高灵敏度法³⁺测定用线性范围为1.5 LOD建立-分别为692μmol/ L和87 nmol / L。然后将荧光探针用于检测Fe ³⁺在自来水中，煤石，粉煤灰和食品样品中成功进行检测。此外，所制备的BNSCD可在pH 1.60-7.00范围内用作新型pH荧光探针，这可归因于BNSCD表面上羧基的质子转移。更重要的是，pH荧光探针具有快速，实时和低毒性的特点，可用于HIC，HIEC，LO2和SMMC7721细胞的细胞内pH荧光成像。鉴于其简单性，及时响应性和出色的兼容性，预制的BNSCD在水质和固体废物监测，食品检测，体外细胞内pH值实时测量中显示出潜在的应用。