Liu Lin, Chen Lu, Liang Jiangong, Liu Lingzhi, Han Heyou
State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, China.
J Anal Methods Chem. 2016;2016:4939582. doi: 10.1155/2016/4939582. Epub 2016 Mar 16.
A ratiometric probe for determining ferric ions (Fe(3+)) was developed based on nitrogen-doped carbon dots (CDs) and rhodamine B isothiocyanate (RhB), which was then applied to selective detection of Fe(3+) in PB buffer solution, lake water, and tap water. In the sensing system, FePO4 particles deposit on the surface of CDs, resulting in larger particles and surface passivation. The fluorescence (FL) intensity and the light scattering (LS) intensity of CDs can be gradually enhanced with the addition of Fe(3+), while the FL intensity of RhB remains constant. The ratiometric light intensity of CDs LS and RhB FL was quantitatively in response to Fe(3+) concentrations in a dynamic range of 0.01-1.2 μM, with a detection limit as low as 6 nM. Other metal ions, such as Fe(2+), Al(3+), K(+), Ca(2+), and Co(2+), had no significant interference on the determination of Fe(3+). Compared with traditional probes based on single-signal probe for Fe(3+) detection, this dual-signal-based ratiometric probe exhibits a more reliable and stable response on target concentration and is characterized by easy operation in a simple fluorescence spectrophotometer.
基于氮掺杂碳点（CDs）和异硫氰酸罗丹明B（RhB）开发了一种用于测定铁离子（Fe(3+)）的比率型探针，随后将其应用于PB缓冲溶液、湖水和自来水中Fe(3+)的选择性检测。在传感系统中，磷酸铁颗粒沉积在CDs表面，导致颗粒变大和表面钝化。随着Fe(3+)的加入，CDs的荧光（FL）强度和光散射（LS）强度会逐渐增强，而RhB的FL强度保持不变。CDs LS和RhB FL的比率光强度对0.01 - 1.2 μM动态范围内的Fe(3+)浓度进行定量响应，检测限低至6 nM。其他金属离子，如Fe(2+)、Al(3+)、K(+)、Ca(2+)和Co(2+)，对Fe(3+)的测定没有显著干扰。与基于单信号探针检测Fe(3+)的传统探针相比，这种基于双信号的比率型探针在目标浓度上表现出更可靠和稳定的响应，并且其特点是在简单的荧光分光光度计中操作简便。
