Shang Qiuwei, Zhou Zhixin, Shen Yanfei, Zhang Yuye, Li Ying, Liu Songqin, Zhang Yuanjian
Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, School of Chemistry and Chemical Engineering, Southeast University , Nanjing 211189, China.
Medical School, Southeast University , Nanjing 210009, China.
ACS Appl Mater Interfaces. 2015 Oct 28;7(42):23672-8. doi: 10.1021/acsami.5b07405. Epub 2015 Oct 13.
As an emerging semiconductor, graphite-phase polymeric carbon nitride (GPPCN) has drawn much attention not only in photocatalysis but also in optical sensors such as electrochemiluminescence (ECL) sensing of metal ions. However, when the concentrations of interfering metal ions are several times higher than that of the target metal ion, it is almost impossible to distinguish which metal ion changes the ECL signals in real sample detection. Herein, we report that the dual-ECL signals could be actuated by different ECL reactions merely from GPPCN nanosheets at anodic and cathodic potentials, respectively. Interestingly, the different metal ions exhibited distinct quenching/enhancement of the ECL signal at different driven potentials, presumably ascribed to the diversity of energy-level matches between the metal ions and GPPCN nanosheets and catalytic interactions of the intermediate species in ECL reactions. On this basis, without any labeling and masking reagents, the accuracy and reliability of sensors based on the ECL of GPPCN nanosheets toward metal ions were largely improved; thus, the false-positive result caused by interferential metal ions could be effectively avoided. As an example, the proposed GPPCN ECL sensor with a detection limit of 1.13 nM was successfully applied for the detection of trace Ni(2+) ion in tap and lake water.
作为一种新兴的半导体，石墨相聚合氮化碳（GPPCN）不仅在光催化领域备受关注，在诸如金属离子的电化学发光（ECL）传感等光学传感器方面也备受瞩目。然而，当干扰金属离子的浓度比目标金属离子高几倍时，在实际样品检测中几乎不可能区分是哪种金属离子改变了ECL信号。在此，我们报道仅通过GPPCN纳米片在阳极和阴极电位下分别发生的不同ECL反应可激发双ECL信号。有趣的是，不同的金属离子在不同的驱动电位下对ECL信号表现出明显的猝灭/增强作用，这可能归因于金属离子与GPPCN纳米片之间能级匹配的多样性以及ECL反应中中间物种的催化相互作用。在此基础上，无需任何标记和掩蔽试剂，基于GPPCN纳米片ECL检测金属离子的传感器的准确性和可靠性得到了很大提高；因此，可以有效避免由干扰金属离子引起的假阳性结果。例如，所提出的检测限为1.13 nM的GPPCN ECL传感器已成功应用于自来水和湖水中痕量Ni(2+)离子的检测。
